Laboratory Operations and Quality Management

Good day. So for this session, we are to discuss selected concepts with regards to laboratory operations. So specifically, we are to include topics on quality management, we have diagnostic efficacy, we have selected concepts on, I mean, selected instrumentation techniques, as well as laboratory mathematics. So I've only included those topics that are really high yield in the ASCP examination. So first, let us define what quality management systems are. So this is a process-oriented, coordinated, and organized system of activities that encompasses the totality of all functions involved in achieving quality and maximum customer satisfaction. And quality management systems are designed in order to detect errors and prevent them from occurring again and from recurring. However, It does not guarantee an error-free laboratory. So quality management system should include all three phases of the total testing process and not just the analytical phase, but it should also include the pre-examination, the examination, and the post-examination variables. So there are 12 essential elements or building blocks that should be addressed in order for in order for us to ensure quality for a particular quality management system. So this includes organization. So when we say organization, this tackles about the roles and responsibilities of the different personnels composing a laboratory. Of course, the personnel. So this includes job qualifications, descriptions. Of course, the training of the personnels. Competency assessment and orientation. So prior to the start of, I mean, usually after the hiring process, the personnel or the medtech, for example, must be really oriented on the process flow inside the laboratory. So, of course, each institution, they usually are specifying yung... mga kailangan nilang credentials in order for you to be hired. So we have what we call credential requirements. So this includes, let's say for example, yung mga specific certification. For example, yung ASAPI. So may mga institution that requires this particular certification in order for you to be hired. Of course, training. So that's why meron tayong mga kailangan yan, yung training records natin for hiring. And of course, competency. And yung competency, it has to be assessed regularly. Usually, every after six months or pwedeng anwal na assessment. That's why yung isang institution, it must have its own KPIs or yung tinatawag natin na key performance indicators because kailangan ito in order for the assessments to really be objective. Next, of course, equipment and instrument management. So this includes purchasing, inventory, calibration. We also have process control. So yung quality control, nandito yan. Yung sample management, yung validation of test methods, the verification of methods, and yung acceptability ng mga reagents na ginagamit natin in the laboratory. Of course, it also includes information management. So most of the laboratories today, especially the high-end ones, are now using what we call a laboratory information system. So this is part of information management. So of course, what's included in our laboratory information system is what we call data security. Of course, the... The incorporation of laboratory information system in the process of the laboratory also ensures a smooth flow of laboratory processes. So usually from requisitions, data entry, records, and patient reports are now generated through the computer. Next, of course, we have documents and records. For this, we need the proper flow of our records in the laboratories from the time that it is created, if there are revisions that have to be made, approval, the control, the distribution of these records, the review of these records, the storage, and the retention. So of course, meron tayong mga... specifications when it comes to the retention of patient records, especially if these records are, let's say, of medical legal or usually yung mga histopathology records, they have to be retained in the laboratory for, I mean, indefinitely. Also, it includes occurrence management, identification, and correction of non-conformities. Yung mga complaints ng pasyente. So it has to be resolved. It has to be investigated. And of course, we need to implement certain corrective actions based on these occurrences. Next, we also have assessment. So assessment that is not just internal but also external assessment. So that's why meron tayong mga internal and external audits periodically and a laboratory. We also have process improvement. So part din ito talaga ng tinatawag natin na continuous quality improvement. Customer service. And of course, facilities and safety. So I just want you to take note of these essential elements for a quality QMS program. Next, let us define quality improvement. So quality improvement is a system. or process interventions aimed at raising product quality. So under your quality improvement, meron tayong tinatawag na parang iteration of quality improvement. Yan yung tinatawag natin na continuous quality improvement. So yung pag-improve kasi ng isang institution, it's not a dead-end process. It has to be a cycle. A cycle of continuously identifying opportunities, make changes, And of course, measure the improvement. And whenever we identify that there is a better way or we can implement in order to better our services, so it has to be implemented. Next, we have quality assurance. So this is proactive systematic activities to provide confidence that the quality requirements will be met. And quality assurance activities are designed in order to prevent defects and identify system variations or barriers to quality. And lastly, the analytical component of a quality assurance program is quality control. So this includes processes and procedures that are used in order to detect analytical errors before the release of base and test results. and included in your quality control is that we have to ensure accuracy, precision, and reproducibility of a test system over time and under various operating conditions. So for quality control, there are two types of that. We have internal quality control and external quality control. So when we say internal, the other term for this is intra-laboratory, intra-lab. So this is what we do on a day-to-day basis. So it allows identification of analytic errors within a week cycle. Through this, we are able to detect changes in performance between the present operation and the stable operation. And we also have external QC, which we also call inter-laboratory QC. Here in the Philippine setting, we have what we call yung tinatawag natin na NECWAS wherein all laboratories must be enrolled in a national quality control, quality assurance scheme wherein periodically yung mga participating laboratories are nakaka-receive sila ng mga proficiency testing samples. And this is to ensure that the methodologies that are done in a laboratory is at par, of course, with... What is the established standard? So maintenance of external quality control is important for ensuring long-term accuracy of the analytical methods in the lab. So as what I've mentioned, part of the external quality control is what we call proficiency testing. And we have here the PT programs. So I included here, since you will be taking the ASCPI exam, I included the PT program as required by the CLIA requirement. So. For this, the participants receive three surveys per year, and each survey consists five samples. So the laboratory performs the indicated testing and reports results to the surveying agency. And of course, when testing these laboratory samples, I mean when testing these proficiency testing samples, we sometimes call them PT samples or blind samples, the lab must treat these samples as it would a patient sample. So magkaiba yung ating PT grading, nakadepende if we are using commutable samples or non-commutable samples. Now ano ba yung pinagkaiba ng dalawa? When we say commutable samples, these samples can be traced to a reference method. So take note natin dyan. Okay, can be traced. And since it is traced to a reference method, if we are using commutable samples, it's like that we are comparing our results with a true value. So for commutable samples, yung ginagamit natin na basis in proficiency testing grading is the mean and the SD of the reference method. So we are using the mean. and the standard deviation of the reference method. So that is for commutable samples. Now for non-commutable samples, still we are using the mean and the standard deviation, but this time, we are using the mean and the standard deviation of the peer group. So when we say peer group, This includes all participating laboratories that are using the same methodology. Okay? So, nakabase ito sa peer group. Okay? So, that means all participating laboratories. using the same methodology. So, kumbaga, lahat ng mga results ng mga participating laboratories na ito, dinedefine, dinedefine out of the values of these participating laboratories, inestablish yung mean, tsaka yung standard deviation. And yun yung nagiging basis in the PT grading. So that is in the case of non-commutable samples. So between the two, of course, mas preferred itong mga commutable samples kasi syempre this is based on the reference method. Okay? So how do we know if the performance of the laboratory in a certain proficiency testing survey is considered to be satisfactory? That is when the laboratory is able to achieve Thank you. at least 80% of the sample results are graded as acceptable. So since we received 5 samples for each survey, it means 4 out of 5 samples must be acceptable. So what does it mean when we say acceptable? The value is considered acceptable if it is within 2. It is graded as needs improvement if it is within 2 to 3 SD. And it is unacceptable if the value is falling outside 3 SD. So that's it for... proficiency testing programs. So now let us proceed to statistical quality control. So of course, I've mentioned about the mean standard deviation. So medyo basic ito, but still we have to know how to properly solve for these values in the ASCP exam. Sa katunayan, during my exam, I was asked to solve for the coefficient of variation and I was given five hemoglobin values. So, pinasolve sa akin yung coefficient of variation. So, before you arrive to that solving, may mga certain elements ka muna na kailangan mong isolve. So, this is also important in the ASAP exam. So, first we have the different measures of central tendencies. So, that includes mean. Pag sinabi nating mean, That is the statistical term for average. So how do we solve for this? All we have to do is to add all values and divide them by the number of values. Next is yung tinatawag natin na median. So median is the middle observation provided dapat naka-arrange muna yung mga data in order or they are ranked muna. And we are to identify what is the upper. Sorry, what is the middle value? So when we are using a median, the data points are divided into upper and lower values. Next, yung tinatawag natin na mode. So mode is simply defined as the most frequent observation or the most frequent data. And lastly, we have mid-range. So mid-range is basically the average of the highest. and the lowest value in a data set. So just take note that these measures of central tendencies are actually indicators of accuracy. Next, let's proceed to the different measures of spread or dispersion. These are indicators of precision. So when we say precision, how far is one value from the other? Or this measures the distance of the different values from each other. So first, consider it to be the simplest measure of precision. Yan yung tinatawag natin na range. So this is simply the difference between the largest and the lowest value in a data set. So if you are asked to solve for the range, all you have to do is to deduct the lowest value from the highest value. So that is now the range. Next. Ito naman yung pinakakomun na ginagamit na measure of spread or precision. We have standard deviation. Okay? Standard deviation. So, dapat marunong kung ano yung formula ng ating standard deviation. The formula for this is the formula for SD equal to the square root of a summation. of x minus mean squared over n minus 1. So that is standard deviation. Okay? So next is SD of a set of data points divided by the mean. So ito yung recall question sa exam ko. Ito yung tinatawag natin na coefficient of variation. So coefficient of variation is considered to be the index of precision. And lastly, average of the squared distances of all values from the mean. So simply, this is SD squared. So whatever your SD value, all you have to do is to multiply it by itself. So yan yung tinatawag natin na variance. So maki-take note lang ng mga formulas. I already gave you the formula for standard deviation. Pag ganito yung formula, This is the formula for standard deviation. The formula for variance is parang ganito din. So, diba? Yung variance is SD squared. So, formula of SD minus mean squared divided by N minus 1. And if you are going to square this, that's variance. Or pwede din nakunin mo na lang yung square root. So, variance is simply the summation of X minus mean squared over n minus 1. So that's the formula of variance. Now, for the formula of coefficient of variation, CV is equal to your standard deviation divided by your mean value. CV is your standard deviation divided by mean times 100. So, yan yung mga formula na kailangan natin i-take. So, itong mga statistical measures na ito na mention ko, these are actually terms that are used sa tinatawag natin na descriptive statistics. So, we are referring it as descriptive statistics. statistics if we are only describing a single set of data. So for example, you are asked what is the mean of the glucose value for a certain month or for a certain period. So it means you just define or describe the set or the data set for a certain period of time. But when you start to compare two data sets. Yan yung tinatawag natin na compare. comparative statistics or inferential statistics. And examples of tools for that is yung tinatawag natin na T-test. This is a recall question, yung T-test. Actually, definition lang naman yung nandun sa tanong. And we have F-test. So, pakiteak note lang ng difference ng dalawa. Pag sinabi nating T-test, we are comparing the accuracy of two sets of data. by comparing their means. So, dito, you are checking if there is a statistical significant difference between the mean of two groups of data. So, kanina I mentioned that mean is a measure of accuracy. So, that means when you are doing a t-test, you are actually comparing the accuracy of two datasets. Pag sinabi naman nating f-test, this is used to determine whether there is a statistically significant difference between the standard deviation of two groups of data. And since SD yung kinukompare natin dito, and earlier I mentioned that standard deviation is a measure of precision, when you are doing an F-test, you are actually comparing the precision of two datasets. Okay? So, Let us now proceed to quality control charts. So I only included here yung dalawa na pinaka-familiar tayo. So first, we have the Gaussian curve. And the Gaussian curve is actually the inspiration of the most commonly used quality control chart today. Yan yung tinatawag natin na Schuhart-Levy-Jennings chart. Kasi technically, yung Schuhart-Levy-Jennings chart para siyang Gaussian curve na pinahiga. Okay? But the points here, the concepts here are the same. Okay? So, pag sinabi nating Gaussian curve, it actually divides the data into three. Meron tayong tinatawag na 1SD range, 2SD range, and 3SD range. So, ano yung ibig sabihin ito? So, pag sinabi nating 1SD range, ito yun. So, this is the 1SD range. That means 68.2% of the data will fall. inside the 1SD range. Okay? Pag sinabi naman nating 2SD range, 95% of the data will fall within the 2SD range. And yung 3SD range, it includes 99% of the data. Now, in the laboratory, meron tayong tinatawag na confidence range. And every time na naririnig natin yan, guys, yung confidence range, that means yan yung 2SD range. Okay? So, pag sinabing 2SD range or pag sinabing confidence range, we are already expecting that 5% of the control values will fall outside it. Okay? Kasi pag sinabing nating 2SD range or pag sinabing nating confidence range, that only includes 95% of the values. Or let's say in the case of controls, 95% of the control values. So, we're really assuming that... that 5% of our control values are expected to fall outside the confidence range. So in the Gaussian curve, take note that on the x-axis, what we are plotting here are the actual or the assay values. The actual or the assay values. And on the y-axis, we are plotting the frequency here. So pag sinabi nating frequency, kumbaga this tells us on the number of times each value was seen. Now, the most commonly used quality control chart in the laboratory is the Schuhart-Levy-Jennings chart. And this time, what we are plotting on the y-axis are the control values. I'm sure we all know this, the Schuhart-Levy-Jennings chart. And the one that is plotted on the x-axis are the dates of analysis. Okay? So, Of course, in order for us to make our interpretations of the Schuhart-Levy-Jennings chart objective, that's why meron tayong kriteriya. So yan yung tinatawag natin na Westgard rules. So yung Westgard rules, ito yung nagsiserve na kriteriya natin in interpreting the values that are plotted on the Schuhart-Levy-Jennings chart. So I only included here the six basics. na Westgard rules. So three of these are telling us that there is a random error and three of them are telling us na merong systematic error. So yung nasa taas, yung 1-2-S, 1-3-S, tsaka R-4-S, they usually detects or indicates presence of random error and itong 2-2-S violation, 4-1-S violation, and 10-X rule violation, These violations are telling us that there is a systematic error or systematic bias. So first, we have the 1-2-S rule violation. This is the only Westgard rule violation wherein we are still able to accept the run. We will still accept the run because this is a warding rule. So the rest of the violations would already require us to reject the run. So next, we have the 1, 3S rule violation. So just take note that this detects imprecision. This detects imprecision. So pag merong imprecision, merong random error. Yung R4S violation, this detects random error. Yung ating 2, 2S violation, this is capable of detecting both imprecision and systematic. bias. Just take note that it detects imprecision and systematic bias. Next, we have the 401S rule violation. This one detects systematic bias. Bias is the other term for error. And also similar with the 10x rule or the 10 mean. It is also called 10 mean rule violation. It also detects systematic bias. So I also included here the different steps on how to deal with a control. that is outside the acceptable range. Because I encountered a recall question that is situational, that MedTech is encountering difficulty in the difficulty that the control value entered the confidence range. So what will it do? So we have, it depends if it didn't enter one time or even after you... you did the rerunning, hindi pa rin siya pumapasok. So, nakadepende dun kung ano yung magiging course of action natin. Okay? So, we have here eight steps. So, first, siyempre, considering that the control value is not within the confidence range, you are not capable, or that will tell us na mali-mali yung ginagawa nating testing. So, you cannot release the patient test results. Kasi ibig sabihin nun, hindi siya... hindi siya reliable. Kasi nga, hindi pasok yung control range natin. So, you are to hold the patient results until the problem is resolved. So, if a control value is inaccurate, the patient results might also be inaccurate. Next, we are going to rerun the control. So, only once. So, the first time that we run it, hindi siya pumasok. So, we are to rerun it again. Okay? So, The inaccurate control value might have been due to a random error only. So baka the second time around na nirun mo yung control, baka pumasok na siya. But if the control is still out, Okay? Hindi pa rin siya pumasok sa confidence range. So you are going to run a new vial of control or another with a different lot number. Kasi baka yung problema dun mismo sa control na ginagamit mo. Or maybe it's already outdated or baka improperly stored siya or baka contaminated siya. So you are going to get a new control and yun yung gagamitin mo sa machine. If the control is still out, okay? Kahit yung bagong kinuha mo na, If the control is still out, look for and correct any problems, then run the control. So, ano yung mga possible problems? Bakit hindi pumapasok yung control even after we change it already to a new one? So, maybe the problem is in the reagents. So, baka yung reagents mo konti na lang, outdated, improperly stored, or contaminated. Or baka yung preventive maintenance mo is already overdue. Or baka merong mechanical problem. baka may clot dun sa specimen or baka dun sa loob ng machine, for example. So, resulting to the failure of making the control fall within the range. So, if the control is still out, even after you already check for all those possible sources of error, then you recalibrate the machine and then you run the control. Okay? So, Maybe the reason why the control will not enter is because the calibration on the first place is erroneous. Next, if the control is still out even after you recalibrated the machine, then you get assistance. So, we know that our machines are sometimes tied up with companies. So, usually, we call their services, their engineers. pumunta sa laboratory in order to check the machine. And once the problem is resolved, then it has to be documented. And yung corrective action na ginawa doon has to be documented also. So this will provide a record for future reference and to determine and avoid the same problem from happening again. And lastly, you evaluate all patient results during the rejected run. and compare it with the last run with acceptable quality control. And repeat the tests and issue corrected reports as needed. Because of course, the first one, most likely, our results are really erroneous. So we have to repeat sample testing again. Because again, we are obliged to be able to release reliable results to our patients. So far, that's all for our quality control concepts. Okay, so let us now proceed to diagnostic efficacy or efficiency. So, itong mga values na ito, they are usually present sa mga ginagamit natin na test methods. Through these values, malalaman natin saan ba mas okay or saan mas pwedeng gamitin or mas efficient yung isang test method. whether okay ba siyang gamitin na screening method or confirmatory method. And again, that is based on its sensitivity, specificity, positive predictive value, and negative predictive value. I think for this, yung pinaka-importante is marunong tayong mag-solve ng mga values na ito. So when we say diagnostic sensitivity, this is the ability of a test to detect disease and is expressed as the proportion of persons with disease in whom the test is positive. So in simple terms, when we say diagnostic sensitivity, kung baga sa lahat ng taong may sakit, ilan ba dun yung nadidetect ng ating test method? So the formula for this is true positives over true positives. plus false negative. This is it. True positive over true positive plus false negative. Because when we say false negative, those people have pain, but they are not detected by the test method. Okay? Times 100. When we say diagnostic specificity, This is the ability to detect the absence of disease. So, kung baga, sa lahat ng mga taong walang sakit or normal, ilan ba dun yung nabibigyan ng tamang negative result ng ating test method? So, the formula for this is true negative. over true negative plus false positive times 100. So they are expressed in percent. Now be careful with the formula of PPV or positive predictive value kasi halos magkamukha siya with the diagnostic sensitivity formula. So ito naman, this is true positive over true positive plus false positive times 100%. So pag sinabi natin, Positive predictive value, this is the chance of an individual having a given disease or condition if the test is abnormal. So, kung baga, sa lahat ng positive result na nire-release or sa lahat ng positive result ng isang test method, ilan ba dun yung tama or ilan ba dun yung tunay na positive? So that means if the positive predictive value of a test method is high, that means most likely, tama yung nabibigay niya na positive result. So in contrast, pag sinabi naman natin na negative predictive value, kung baga sa lahat ng negative results ng isang test or ng isang method, ilan ba dun yung tunay na negative? So that is true negative over true negative plus false negative times 100. Okay? So, So... Again, sa sinabi ko kanina, na dito natin malalaman kung saan ba mas okay na gamitin yung isang method. Whether it is to be used as a screening test or as a confirmatory test. So ito lang yung tatandaan natin. If the method is sensitive, usually ginagamit yan sila as a screening test. So sensitive methods are utilized as a screening test. Bakit? The purpose of this is because we do not want to miss a case. We do not want to miss a case. So that means, pag yung isang method ay sensitive, we want to decrease the false negative results. We want to decrease the false negative results. Ayaw natin na mamiss natin na yung isang tao may sakit. pero hindi siya na-detect ng method. However, sometimes because of the sensitivity of a test method, pag masyado siyang sensitive, tumataas yung false positive values. Ito naman yung nagiging disadvantage niya. Tumataas yung mga false positive na value. Kasi sobrang sensitive ng method. Kahit walang sakit yung tao, na bibigyan siya ng positive result. But it's fine. Kasi yung mga screening test, nasusundan niya ng mas specific na method. So, yung mga ginagamit naman, na confirmatory test, they have to be specific. They have to be specific. Why? Because we do not want to misdiagnose a person. So, with the use of specific test, kumbaga, bumaba ba yung chances of giving a false positive result? Okay? Ayaw natin na mabigyan natin ng positive result yung isang taong walang sakit. Okay? However, if the method is too specific, sobrang specific niya, sometimes, namimiss natin, okay, yung pag-detect ng sakit talaga ng tao. So, tumataas, yung chances of having false negative results. Okay? Hindi natin nadidetect na ay itong taong palang, itong taong ito pala ay may sakit talaga kasi sobrang specific ng test method. Okay? So yan yung pagkakasunod-sunod ng testing natin. We are starting with a screening test with a higher sensitivity and yung mga confirmatory tests have to be very specific. Because again, bakit kailangan sensitive yung mga screening test? Because we do not want to miss a case. Okay? And bakit kailangan specific yung mga confirmatory test? Because we do not want to misdiagnose a person. So ako, yung palatandaan ko dito, tinatandaan ko dito yung N. Ito, tatandaan mo yung N. Okay? Sensitive, binababa niya yung false negative result. Specific P, binababa niya yung false positive results. Okay? So next, let's proceed to laboratory mathematics. From time to time, may mga tanong when it comes to... So here we have proportionally equivalent solution and we have delusion equations. Paano natin malalaman if the problem is a proportionally equivalent problem or if the problem is a delusion problem? Pag proportionally equivalent problem, there is no change in concentration. Take note natin dito that there is no change. There is no change. in concentration. Okay? And pag sinabi naman nating delusion equation, syempre pag nag-dedelute tayo, habang tumataas yung delusion, bumababa yung concentration. Diba? So, ibig sabihin, there is change. Okay? In concentration dito. Okay? Change in concentration. So, Malalaman natin yan. Take note natin yung mga relationships na ito. Habang tumataas yung dilution, take note natin na tumataas yung kanyang volume. Kasi pag nagdadagdag tayo ng diluent, siyempre tumataas yung volume ng solution. And yung concentration ng solution bumababa. Bumababa yung concentration ng solution. So, pag yung isang problem ay proportionally equivalent problem, ano yung magiging formula natin for that? So, that would be weight 1 over V1 is equal to weight 2 over V2. Weight 1 over V1 is equal to weight 2 over V2. Pag sinabi naman natin na delusion equation, yan yung C1V1 is equal to C2V2. So, I'll give you a problem here so we can have an example on this type of problems. So, for example, problems of proportionally equivalent solutions. So, for example, this. So let's say if a 5.0 DL deciliter solution contains 4.5 milligrams of bilirubin, how much? How much bilirubin would there be in a 2.0 DL solution? Kung yung 5.0 deciliter daw na solution ay may lamang 4.5 milligrams ng bilirubin, ilan yung laman na bilirubin if kukuha tayo ng 2.0 deciliter ng kaparehong solution? So there is no change in concentration here because we are talking about the same solution. It's just that we are getting an aliquot or a certain value of the entire solution. So again, the formula for this is weight 1 over V1 is equal to weight 2 over So, simple lang naman yan. If yung weight 1 natin is 4.5, kung merong 4.5 milligrams na bilirubin sa 5.0 DL na solution, ilan daw yung bilirubin, that's our weight 2, sa 2.0 deciliter na alikot of the same solution. So, syempre, ikukross multiply lang naman natin yan. Ito yung magiging simplified. Iko cross multiply mo. Diba ganyan? Okay? So ito yung magiging simplified equation. So weight 2 is equal to 4.5 milligrams times 2.0 deciliter over 5.0 deciliter. So cancel natin yung unit na yan. Okay, so 4.5 times 2. That's 9 milligrams divided by 5.0. So I think that would give you 1.8 milligrams of bilirubin. Okay, 1.8 milligrams of bilirubin. So that means kung sa 5.0 deciliter may 4.5 milligrams na bilirubin, sa 2.0 deciliter merong 1.8 milligrams na bilirubin. Okay, so that's an example of a proportionally equivalent solution or equation. Now, pag-dilution naman yung problem, ito. Another example. So, okay, what volume of a 0.5 molar glucose solution It can be made from a 100 ml of a 3 molar glucose stock solution. So, meron tayong 3 molar. na glucose solution, meron tayong 100 ml na 3 molar glucose solution. Ididelute natin ito para makagawa tayo ng 0.5 molar. So ilang ml ng 0.5 molar glucose solution yung magagawa natin. So dito pa lang sa problem, makikita natin that there is a difference in the concentration. Yung stock solution natin, 3 molar yung kanyang concentration. Then we will make a solution that the concentration is 0.5 molar. So if you would notice, the concentration will be low when we dilute a solution. So our formula here is C1V1 is equal to C2V2. C1V1 is equal to C2V2. So our C1, our concentration 1, let's say 3 molar times Young Volume 1 is 100 ml. Concentration 2 is 0.5 molar times V2. The simplified formula is to divide both sides by 0.5. Divide both sides by 0.5 molar. So that would be V2 is equal to 3 molar times 100 ml over 0.5 molar. Okay? So, eliminate natin yung unit na yan. So, that would be 3 times 100. So, that's 600. 3 times 100, rather, is 300 ml divided by 0.5. So, yung volume 2 natin is 600 ml. Okay? So, namemaintain natin yung relationship na sinasabi ko kanina that when we dilute a solution, tumataas yung kanyang concentration. yung unang concentration natin, 100 ml, the resulting concentration is 600 ml. So, tumaas yung kanyang volume, bumaba yung kanyang concentration. From a 3 molar concentration, naging 0.5 molar concentration siya. Okay? So, kailangan lang natin i-analyze na mabuti yung tanong whether it's proportionally equivalent or a dilution equation. Okay? And of course, Huwag kalimutan yung ratio tsaka delusion. Okay? So, napakarami ng recall, no? Napakarami ng delusion problems na lumabas sa ASAP exam. So, ano ba yung pinagkaiba ng dalawa? So, pag sinabi natin na ratio, it's an expression of one part of something, a part of something, per part or per whole. So, Usually, ginagamit natin ito to describe a solute and a solvent or a solute or a solution. So, ito, bigyan ko kayo ng example para masimple. Let's say, nagmix tayo ng 1 ml ng serum plus 4 ml ng saline. So, ano ba yung mga ratios na pwede nating ma-derive from this mixture na ginawa natin? So, pwede tayong talungin, ano yung ratio? ng serum to saline. So that would be 1 is to 4. Pwede tayong tanungin, ano yung ratio ng serum to the total volume of the solution. So that would be 1 is 2, the total volume is 5. You can also reverse it. What is the ratio of saline to serum? What is the ratio of saline to the total solution? What is the ratio of saline to the total solution? You can do that. So it's anything, right? Saline to solution, so that would be 4 is to 5. So that's the ratio. Now, pag sinabi naman natin na dilution, dilution is volume of the solute over the total volume of the solution. So if gagamitin natin yung kaparehong example, our solute here is the serum. Yan yung dinidisolve. So that's 1 and the total volume is 5. So our dilution is 1 over 5. Now, ginagawa natin minsan yung dilution, let's say for example, pag masyadong mataas yung value ng analyte na hindi na kayang imeasure linearly ng ating machine, kailangan natin idilute yung ating serum in order to decrease the concentration of the analyte to a value that is measurable by our machine. Okay? So, since dinilute natin yung serum, whatever the result of the machine, that is not the true value. That is the diluted value. So in order for us to solve for the actual value, we need to multiply it to the so-called dilution factor. And simply, when we say dilution factor, dilution factor is simply the reciprocal of dilution. So if your dilution is 1 over 5, your dilution factor is 5. I'll give you a recall question on ASCP when it comes to dilution. Maka ilang beses na lumabas yung tanong na to. Nagkaroon daw ng flagging sa machine. Diba? Ganoon naman talaga yung nangyayari. Pag masyadong mataas yung concentration ng isang analyte, nagfa-flag yung machine. So, since nag-flag yung machine, yung ginawa ng MedTech is nag-dilute siya by mixing by mixing 0.1 ml of a serum plus 1.9 ml of the diluent. Now, after he did this dilution, he measured the dilution. If I could correctly recall, the measure he measured in the recall question is the LDH value. So nagkaroon daw ng flagging, kaya siya nag-dilute. So after doing the dilution, yung kanyang diluted sample, yun yung ginamit niya na sample dun sa testing. But still, nagkaroon pa rin ang flagging. So ibig sabihin, kahit nag-dilute na siya, yung concentration dun sa diluted sample is still very high that it cannot be measured by the machine properly. So yung ginawa ng MedTech, gumawa siya ng another dilution. So yung una niyang dinilute, dinilute niya ulit. Okay? So yung ginawa naman niya is, if I could correctly recall, parang 2 ml, no? 2 ml of the diluted sample. Yung dinilute niya na kanina, dinilute niya pa ulit. So 2 ml of the diluted sample, okay, plus 3 ml. of the diluent. So dito makikita natin na yung ating serum was diluted twice. So this is an example of a compound dilution. This is an example of a compound dilution. Pag simple dilution, isang beses ka lang nag-dilute. Pag sinabing compound dilution, you diluted the sample several times and you are not using consistent volumes. Because earlier, 0.1 is to 1.9. Now, what he used is 2 is to 3. So, it's not consistent with the volume that he uses. Because if you are consistent with the volumes that you are using, that is an example of a serial delusion. What we see in antibody titer or in MIC, when we dilute an antibiotic, it's a serial delusion. Because we are consistent with the volumes that we use. Ito, hindi tayo consistent. So this is an example of a compound delusion. So how do we get the final delusion in this case? All you have to do is to multiply all of the delusions made. Okay? So yung unang delusion na ginawa niya, ito. ano ba yung dilution natin dito? So this is 0.1 over, that's the volume of the solute, 0.1 ml, over our total volume is 2.0. 1.9 plus 0.1. So this is our first dilution. We could simplify this as to 1 over 20. Diba? Yung ginawa ko, minultiply ko to by 10, minultiply ko din to by 10. So our first dilution is 1 over 20. Now, ano yung pangalawang dilution natin? That is 2 over the total volume is 5. Okay? So this is our second dilution. So for us to get our final, okay? For us to get our final dilution, all we have to do is to multiply the two dilutions. So that's 1 over 20 times 2 over 5. Okay? So that's 1 times 2. That's 2 over 20 times 5. That's 100. So we could simplify this. Pwede siyang maging 1 over 50. So this is now our final dilution. Now, nung minasure daw natin yung diluted, yung finally diluted sample, yung LBH value daw, yung LBH value sa pinakahuling dilution is 120 international units. Yung tanong dun sa exam was, ano daw yung actual? Or what is the value that you will report? What is the actual value or reported value? Of course, you cannot report 120 international units because that is not the actual value of the patient sample. Because 120 international units, that is the diluted value. So for us to get the actual value or the reported value, all we have to do is to multiply the diluted value times our dilution factor. So ano yung dilution factor natin? Ito. Okay? Reciprocal, diba? So yung baliktad. So 50 over 1, that's 50. Okay? So 120 times 50, which is our dilution factor, that would give us 6,000 international units. So this is our reported value. So yan po yung example ng problem sa dilution. Okay? So, next is, of course, yung ating analytical techniques. So, syempre, huwag na huwag kalimutan yung spectrophotometer. Medyo basic ito, pero may mga recall questions pa din when it comes to the spectro. So, here's the basic configuration of our spectrophotometer. So, we have here our light source. So this is our light source So it provides polychromatophilic Or polychromatic rather Light And it must generate sufficient energy To measure the analyte of interest So this is our light source So our light source Differ depending on What will be Our spectrophotometric work If we are to use UV Infrared or Visible spectrum So usually, pag visible, yung pinaka ginagamit natin dito is the tungsten. Okay? The tungsten filament na lamp. Okay? The tungsten lamp. Next, we have here our entrance slit. So the purpose of the entrance slit, okay, is to minimize stray light. Okay? And prevent the entrance of scattered light into the monochromator system. Okay? So, ito yung naging recall question sa exam. Yung tinatawag natin na monochromator. Okay? Yung monochromator, tinatawag din yan siya na wavelength selector because it isolates the specific wavelength needed for the measurement. I'm sure you could relate kasi for example, if we want to measure, let's say, bilirubin, kailangan natin 450 nanometers. If we want to perform, let's say, the biuret technique sa protein determination, on. 560 nanometers yung ginagamit natin dun. So, kabaho yan ng ating monochromator or ng ating wavelength selector to select the wavelength needed for the measurement. Okay? So, ito, no? This is our monochromator system. Okay? Next is, ito. This is our exit slit. Okay? So, that is the exit slit. So, the purpose of the exit slit is to allow only a narrow fraction of light to reach the qubit. Okay? Cubette. So this is our cubette. So it holds the solution whose concentration is to be measured. So it's also called a sample holder. Okay? Next, we have our photo detector. Okay? The photo detector. So this is it. So usually, the photo detector is also there, the so-called signal processor. Because the photo detector... dinidetect niya yung transmitted light. So this is the transmitted light. Dinidetect niya yan and kinoconvert niya yan into a photoelectric energy. In order for us to generate a numerical value from it. And that numerical value is being displayed sa tinatawag natin na read-out device. So yung read-out device na yan, pwede siyang LED display. It could be the computer monitor. Ito yung ating... Read-out device. So that's the basic configuration of our spectrophotometer. So for the quality control of the spectrophotometer, may dalawang terms ako na I want you to really remember. First, yung tinatawag natin na wavelength accuracy. Ano ba ibig sabihin ito? Okay, wavelength accuracy. So it implies that a photometer or a spectrophotometer is measuring at the wavelength that it is set to. So this can be assessed easily using special glass-type optical filters. So this wavelength accuracy, it tells us about the function of our monochromator. If we set it to isolate, let's say, 450 nanometer, it really isolates the wavelength. So that's what we meant by wavelength accuracy. So, ano yung mga examples ng glass-type optical filters na ito na pwede natin gamitin in order to assess if our spectrophotometer has wavelength accuracy? So, pwede tayong gumamit ng tinatawag na didymium filter and pwede tayong gumamit ng homeom oxide filter. So, take note lang ng pan- pinagkaiba ng dalawa, yung didymium filter, it has a broad absorption peak. It has a broad absorption peak. So usually, this is at 600 nanometers. Whereas, yung homeium oxide filter naman, meron siyang multiple, okay, multiple sharp, okay, absorption peaks, okay? Multiple sharp absorption peaks. And usually, this is at 360 nanometers, okay? Next is defined as the ability of a photometric system to yield a linear relationship between the radian power incident upon its detector and the concentration of the solution being measured. Yan naman yung tinatawag natin na wavelength linearity. Ibig sabihin ito, pag sinabi natin na wavelength linearity, kumbaga, ito yung nagbibigay sa atin ng parang assurance na whatever the result that is given out by our spectrophotometer, it really represents the amount of absorbing substances doon sa ating solution. So that is wavelength linearity. And I've included here selected analytical techniques. So, please take note because I'll mention because a number of these also came out in my exam. Very simple lang naman yung tanong. Nagbibigay sila na parang analyte and ano daw yung technique na ginagamit. So first, I don't know. Bakit ko pa in-include dito? This one is an obsolete technique already, yung tinatawag natin na flame emission photometry. Flame emission photometry. So this one measures light emitted by easily excited atoms. So yung nangyayari dito, with the use of heat or radiant energy, na-excite natin yung mga atoms. And when they are excited, they are releasing light. They are releasing energy. So, syempre, the color of the light, or the... In the case of flame emission photometry, kasi nag-change yung kulay ng flame. And the color of the flame changes depending on the substance being measured. That's why meron tayong sodium yellow, potassium violet, calcium red-orange, magnesium blue, mga ganyan. And the intensity of the color is depending on the concentration of the substance being measured. So just take note, the internal standards used here are lithium and cesium. But FEP is already obsolete. Now, this one measures light absorbed by ground state atom. So when we say ground state, it means unexcited. That's why this method is used for analytes that are not easily excited by the flame. Yung mga hindi mabilis na e-excite, minimeasure na lang sila sa kanilang ground state. Yan yung tinatawag natin na atomic absorption spectrophotometry. Atomic absorption spectrophotometry. So example guys of analytes that are not easily excited are calcium and... magnesium. Calcium and magnesium. So, take note, recall question, take note yung ating hollow cathode lamp. Yung hollow cathode lamp, kasi ito yung ginagamit natin na light source sa AAS. This is the light source for atomic absorption spectrophotometry. Next, atoms absorb light of a specific wavelength. and emit light of a longer wavelength. This is a recall question. Yung nandun is binigay yung definition ng method, tapos pina-identify kung anong method siya. So that is fluorometry. Okay? Fluorometry. So take note guys, na isa sa mga tatandaan natin na characteristic ng fluorometry is that it is sensitive and specific. Okay? Sensitive and specific. Next. Measures the reduction in light transmission by particles in suspension. So usually ginagamit ito to measure proteins in urine and CSF. We have turbidimetry. Turbidimetry. And measures light at an angle from light source. Usually for the measurement of antigen-antibody reactions, this is nephelometry. Nephelometry. So yung pinagkaiba ng dalawa is the positioning of the photodetector. So for example, if this is your light source, let's say this is your light source, and this is the sample holder, pag sinabi nating turbidimetry, ito yung kanyang photodetector. Pag sinabi nating nephelometry, ito yung kanyang photodetector. The photodetector is positioned at an angle. Kasi sa turbidimetry, kumbaga, minimesure mo yung light na nabablock ng solution. Pag sinabi nating nephelometry, minimeasure natin yung light na sinascatter ng solution. That's why the photodetector is positioned at an angle. Okay? Next, ito yung lumabas aking exam. Very simple yung tanong. Ano daw yung principle na ginagamit sa pH determination? So that is potentiometry. Okay? Potentiometry. So ito din yung principle sa tinatawag natin guys na ion selective electrode. Okay? ion, selective electrode. Okay? So for pH and PCO2 determination, so that is potentiometry. Ito yung lumabas sa akin. Principle for pH determination. Next, this is used for measurement naman of PO2. Okay? So it measures current flow produced by oxidation reaction. So ito yung tinatawag natin na amperometry. Okay? Amperometry. Or tinatawag din siya na polarography. Okay? Polarography. So ginagamit siya for PO2 determination. Diba? May electrode tayo for PO2. Yung tawag natin doon is the Clark electrode. Yan. So PO2 determination, amperometry. Pag pH and PCO2 determination, potentiometry naman yun. Kung Clark electrode yung ginagamit for PO2, yung ginagamit sa PCO2 naman is the severing house electrode. Okay? Severing house electrode. Tapos for pH determination, glass electrode lang yan. Okay? Next, involves measurement of the quantity of electricity needed to convert an analyte to a different oxidation state. Ginagamit siya usually to measure chloride ions, might it be in the serum, the plasma, the CSF, or sweat samples. Ito yung collometry. And lastly, involves measurement of the resulting current after a potential is applied to an electrochemical cell. Usually, ginagamit siya to measure heavy metals. Example of this is... The measurement of lead, yung tinatawag natin na voltammetry. Okay? So, yan po for our selected analytical techniques. Okay? So, pakite-take note lang ng mga nilalagyan ko ng star, ng mga recall question. So, so far, that's all for our topics on laboratory operations. Thank you.

So this is a process-oriented, coordinated, and organized system of activities that encompasses the totality of all functions involved in achieving quality and maximum customer satisfaction. And quality management systems are designed in order to detect errors and prevent them from occurring again and from recurring. However, It does not guarantee an error-free laboratory. So quality management system should include all three phases of the total testing process and not just the analytical phase, but it should also include the pre-examination, the examination, and the post-examination variables.

So there are 12 essential elements or building blocks that should be addressed in order for in order for us to ensure quality for a particular quality management system. So this includes organization. So when we say organization, this tackles about the roles and responsibilities of the different personnels composing a laboratory. Of course, the personnel.

So this includes job qualifications, descriptions. Of course, the training of the personnels. Competency assessment and orientation.

So prior to the start of, I mean, usually after the hiring process, the personnel or the medtech, for example, must be really oriented on the process flow inside the laboratory. So, of course, each institution, they usually are specifying yung... mga kailangan nilang credentials in order for you to be hired.

So we have what we call credential requirements. So this includes, let's say for example, yung mga specific certification. For example, yung ASAPI.

So may mga institution that requires this particular certification in order for you to be hired. Of course, training. So that's why meron tayong mga kailangan yan, yung training records natin for hiring.

And of course, competency. And yung competency, it has to be assessed regularly. Usually, every after six months or pwedeng anwal na assessment. That's why yung isang institution, it must have its own KPIs or yung tinatawag natin na key performance indicators because kailangan ito in order for the assessments to really be objective.

Next, of course, equipment and instrument management. So this includes purchasing, inventory, calibration. We also have process control.

So yung quality control, nandito yan. Yung sample management, yung validation of test methods, the verification of methods, and yung acceptability ng mga reagents na ginagamit natin in the laboratory. Of course, it also includes information management.

So most of the laboratories today, especially the high-end ones, are now using what we call a laboratory information system. So this is part of information management. So of course, what's included in our laboratory information system is what we call data security. Of course, the...

The incorporation of laboratory information system in the process of the laboratory also ensures a smooth flow of laboratory processes. So usually from requisitions, data entry, records, and patient reports are now generated through the computer. Next, of course, we have documents and records.

For this, we need the proper flow of our records in the laboratories from the time that it is created, if there are revisions that have to be made, approval, the control, the distribution of these records, the review of these records, the storage, and the retention. So of course, meron tayong mga... specifications when it comes to the retention of patient records, especially if these records are, let's say, of medical legal or usually yung mga histopathology records, they have to be retained in the laboratory for, I mean, indefinitely.

Also, it includes occurrence management, identification, and correction of non-conformities. Yung mga complaints ng pasyente. So it has to be resolved.

It has to be investigated. And of course, we need to implement certain corrective actions based on these occurrences. Next, we also have assessment.

So assessment that is not just internal but also external assessment. So that's why meron tayong mga internal and external audits periodically and a laboratory. We also have process improvement.

So part din ito talaga ng tinatawag natin na continuous quality improvement. Customer service. And of course, facilities and safety. So I just want you to take note of these essential elements for a quality QMS program.

Next, let us define quality improvement. So quality improvement is a system. or process interventions aimed at raising product quality. So under your quality improvement, meron tayong tinatawag na parang iteration of quality improvement. Yan yung tinatawag natin na continuous quality improvement.

So yung pag-improve kasi ng isang institution, it's not a dead-end process. It has to be a cycle. A cycle of continuously identifying opportunities, make changes, And of course, measure the improvement.

And whenever we identify that there is a better way or we can implement in order to better our services, so it has to be implemented. Next, we have quality assurance. So this is proactive systematic activities to provide confidence that the quality requirements will be met.

And quality assurance activities are designed in order to prevent defects and identify system variations or barriers to quality. And lastly, the analytical component of a quality assurance program is quality control. So this includes processes and procedures that are used in order to detect analytical errors before the release of base and test results.

and included in your quality control is that we have to ensure accuracy, precision, and reproducibility of a test system over time and under various operating conditions. So for quality control, there are two types of that. We have internal quality control and external quality control.

So when we say internal, the other term for this is intra-laboratory, intra-lab. So this is what we do on a day-to-day basis. So it allows identification of analytic errors within a week cycle. Through this, we are able to detect changes in performance between the present operation and the stable operation. And we also have external QC, which we also call inter-laboratory QC.

Here in the Philippine setting, we have what we call yung tinatawag natin na NECWAS wherein all laboratories must be enrolled in a national quality control, quality assurance scheme wherein periodically yung mga participating laboratories are nakaka-receive sila ng mga proficiency testing samples. And this is to ensure that the methodologies that are done in a laboratory is at par, of course, with... What is the established standard?

So maintenance of external quality control is important for ensuring long-term accuracy of the analytical methods in the lab. So as what I've mentioned, part of the external quality control is what we call proficiency testing. And we have here the PT programs. So I included here, since you will be taking the ASCPI exam, I included the PT program as required by the CLIA requirement. So.

For this, the participants receive three surveys per year, and each survey consists five samples. So the laboratory performs the indicated testing and reports results to the surveying agency. And of course, when testing these laboratory samples, I mean when testing these proficiency testing samples, we sometimes call them PT samples or blind samples, the lab must treat these samples as it would a patient sample. So magkaiba yung ating PT grading, nakadepende if we are using commutable samples or non-commutable samples. Now ano ba yung pinagkaiba ng dalawa?

When we say commutable samples, these samples can be traced to a reference method. So take note natin dyan. Okay, can be traced.

And since it is traced to a reference method, if we are using commutable samples, it's like that we are comparing our results with a true value. So for commutable samples, yung ginagamit natin na basis in proficiency testing grading is the mean and the SD of the reference method. So we are using the mean. and the standard deviation of the reference method.

So that is for commutable samples. Now for non-commutable samples, still we are using the mean and the standard deviation, but this time, we are using the mean and the standard deviation of the peer group. So when we say peer group, This includes all participating laboratories that are using the same methodology.

Okay? So, nakabase ito sa peer group. Okay?

So, that means all participating laboratories. using the same methodology. So, kumbaga, lahat ng mga results ng mga participating laboratories na ito, dinedefine, dinedefine out of the values of these participating laboratories, inestablish yung mean, tsaka yung standard deviation. And yun yung nagiging basis in the PT grading. So that is in the case of non-commutable samples.

So between the two, of course, mas preferred itong mga commutable samples kasi syempre this is based on the reference method. Okay? So how do we know if the performance of the laboratory in a certain proficiency testing survey is considered to be satisfactory?

That is when the laboratory is able to achieve Thank you. at least 80% of the sample results are graded as acceptable. So since we received 5 samples for each survey, it means 4 out of 5 samples must be acceptable.

So what does it mean when we say acceptable? The value is considered acceptable if it is within 2. It is graded as needs improvement if it is within 2 to 3 SD. And it is unacceptable if the value is falling outside 3 SD.

So that's it for... proficiency testing programs. So now let us proceed to statistical quality control.

So of course, I've mentioned about the mean standard deviation. So medyo basic ito, but still we have to know how to properly solve for these values in the ASCP exam. Sa katunayan, during my exam, I was asked to solve for the coefficient of variation and I was given five hemoglobin values. So, pinasolve sa akin yung coefficient of variation. So, before you arrive to that solving, may mga certain elements ka muna na kailangan mong isolve.

So, this is also important in the ASAP exam. So, first we have the different measures of central tendencies. So, that includes mean.

Pag sinabi nating mean, That is the statistical term for average. So how do we solve for this? All we have to do is to add all values and divide them by the number of values. Next is yung tinatawag natin na median.

So median is the middle observation provided dapat naka-arrange muna yung mga data in order or they are ranked muna. And we are to identify what is the upper. Sorry, what is the middle value? So when we are using a median, the data points are divided into upper and lower values.

Next, yung tinatawag natin na mode. So mode is simply defined as the most frequent observation or the most frequent data. And lastly, we have mid-range.

So mid-range is basically the average of the highest. and the lowest value in a data set. So just take note that these measures of central tendencies are actually indicators of accuracy. Next, let's proceed to the different measures of spread or dispersion. These are indicators of precision.

So when we say precision, how far is one value from the other? Or this measures the distance of the different values from each other. So first, consider it to be the simplest measure of precision. Yan yung tinatawag natin na range.

So this is simply the difference between the largest and the lowest value in a data set. So if you are asked to solve for the range, all you have to do is to deduct the lowest value from the highest value. So that is now the range.

Next. Ito naman yung pinakakomun na ginagamit na measure of spread or precision. We have standard deviation.

Okay? Standard deviation. So, dapat marunong kung ano yung formula ng ating standard deviation. The formula for this is the formula for SD equal to the square root of a summation.

of x minus mean squared over n minus 1. So that is standard deviation. Okay? So next is SD of a set of data points divided by the mean.

So ito yung recall question sa exam ko. Ito yung tinatawag natin na coefficient of variation. So coefficient of variation is considered to be the index of precision. And lastly, average of the squared distances of all values from the mean.

So simply, this is SD squared. So whatever your SD value, all you have to do is to multiply it by itself. So yan yung tinatawag natin na variance. So maki-take note lang ng mga formulas.

I already gave you the formula for standard deviation. Pag ganito yung formula, This is the formula for standard deviation. The formula for variance is parang ganito din.

So, diba? Yung variance is SD squared. So, formula of SD minus mean squared divided by N minus 1. And if you are going to square this, that's variance. Or pwede din nakunin mo na lang yung square root.

So, variance is simply the summation of X minus mean squared over n minus 1. So that's the formula of variance. Now, for the formula of coefficient of variation, CV is equal to your standard deviation divided by your mean value. CV is your standard deviation divided by mean times 100. So, yan yung mga formula na kailangan natin i-take.

So, itong mga statistical measures na ito na mention ko, these are actually terms that are used sa tinatawag natin na descriptive statistics. So, we are referring it as descriptive statistics. statistics if we are only describing a single set of data. So for example, you are asked what is the mean of the glucose value for a certain month or for a certain period.

So it means you just define or describe the set or the data set for a certain period of time. But when you start to compare two data sets. Yan yung tinatawag natin na compare.

comparative statistics or inferential statistics. And examples of tools for that is yung tinatawag natin na T-test. This is a recall question, yung T-test.

Actually, definition lang naman yung nandun sa tanong. And we have F-test. So, pakiteak note lang ng difference ng dalawa.

Pag sinabi nating T-test, we are comparing the accuracy of two sets of data. by comparing their means. So, dito, you are checking if there is a statistical significant difference between the mean of two groups of data.

So, kanina I mentioned that mean is a measure of accuracy. So, that means when you are doing a t-test, you are actually comparing the accuracy of two datasets. Pag sinabi naman nating f-test, this is used to determine whether there is a statistically significant difference between the standard deviation of two groups of data. And since SD yung kinukompare natin dito, and earlier I mentioned that standard deviation is a measure of precision, when you are doing an F-test, you are actually comparing the precision of two datasets.

Okay? So, Let us now proceed to quality control charts. So I only included here yung dalawa na pinaka-familiar tayo.

So first, we have the Gaussian curve. And the Gaussian curve is actually the inspiration of the most commonly used quality control chart today. Yan yung tinatawag natin na Schuhart-Levy-Jennings chart. Kasi technically, yung Schuhart-Levy-Jennings chart para siyang Gaussian curve na pinahiga. Okay?

But the points here, the concepts here are the same. Okay? So, pag sinabi nating Gaussian curve, it actually divides the data into three. Meron tayong tinatawag na 1SD range, 2SD range, and 3SD range.

So, ano yung ibig sabihin ito? So, pag sinabi nating 1SD range, ito yun. So, this is the 1SD range. That means 68.2% of the data will fall. inside the 1SD range.

Okay? Pag sinabi naman nating 2SD range, 95% of the data will fall within the 2SD range. And yung 3SD range, it includes 99% of the data.

Now, in the laboratory, meron tayong tinatawag na confidence range. And every time na naririnig natin yan, guys, yung confidence range, that means yan yung 2SD range. Okay? So, pag sinabing 2SD range or pag sinabing confidence range, we are already expecting that 5% of the control values will fall outside it.

Okay? Kasi pag sinabing nating 2SD range or pag sinabing nating confidence range, that only includes 95% of the values. Or let's say in the case of controls, 95% of the control values.

So, we're really assuming that... that 5% of our control values are expected to fall outside the confidence range. So in the Gaussian curve, take note that on the x-axis, what we are plotting here are the actual or the assay values.

The actual or the assay values. And on the y-axis, we are plotting the frequency here. So pag sinabi nating frequency, kumbaga this tells us on the number of times each value was seen. Now, the most commonly used quality control chart in the laboratory is the Schuhart-Levy-Jennings chart. And this time, what we are plotting on the y-axis are the control values.

I'm sure we all know this, the Schuhart-Levy-Jennings chart. And the one that is plotted on the x-axis are the dates of analysis. Okay?

So, Of course, in order for us to make our interpretations of the Schuhart-Levy-Jennings chart objective, that's why meron tayong kriteriya. So yan yung tinatawag natin na Westgard rules. So yung Westgard rules, ito yung nagsiserve na kriteriya natin in interpreting the values that are plotted on the Schuhart-Levy-Jennings chart.

So I only included here the six basics. na Westgard rules. So three of these are telling us that there is a random error and three of them are telling us na merong systematic error. So yung nasa taas, yung 1-2-S, 1-3-S, tsaka R-4-S, they usually detects or indicates presence of random error and itong 2-2-S violation, 4-1-S violation, and 10-X rule violation, These violations are telling us that there is a systematic error or systematic bias.

So first, we have the 1-2-S rule violation. This is the only Westgard rule violation wherein we are still able to accept the run. We will still accept the run because this is a warding rule.

So the rest of the violations would already require us to reject the run. So next, we have the 1, 3S rule violation. So just take note that this detects imprecision.

This detects imprecision. So pag merong imprecision, merong random error. Yung R4S violation, this detects random error.

Yung ating 2, 2S violation, this is capable of detecting both imprecision and systematic. bias. Just take note that it detects imprecision and systematic bias. Next, we have the 401S rule violation.

This one detects systematic bias. Bias is the other term for error. And also similar with the 10x rule or the 10 mean. It is also called 10 mean rule violation.

It also detects systematic bias. So I also included here the different steps on how to deal with a control. that is outside the acceptable range.

Because I encountered a recall question that is situational, that MedTech is encountering difficulty in the difficulty that the control value entered the confidence range. So what will it do? So we have, it depends if it didn't enter one time or even after you... you did the rerunning, hindi pa rin siya pumapasok.

So, nakadepende dun kung ano yung magiging course of action natin. Okay? So, we have here eight steps. So, first, siyempre, considering that the control value is not within the confidence range, you are not capable, or that will tell us na mali-mali yung ginagawa nating testing.

So, you cannot release the patient test results. Kasi ibig sabihin nun, hindi siya... hindi siya reliable. Kasi nga, hindi pasok yung control range natin. So, you are to hold the patient results until the problem is resolved.

So, if a control value is inaccurate, the patient results might also be inaccurate. Next, we are going to rerun the control. So, only once.

So, the first time that we run it, hindi siya pumasok. So, we are to rerun it again. Okay?

So, The inaccurate control value might have been due to a random error only. So baka the second time around na nirun mo yung control, baka pumasok na siya. But if the control is still out, Okay? Hindi pa rin siya pumasok sa confidence range. So you are going to run a new vial of control or another with a different lot number.

Kasi baka yung problema dun mismo sa control na ginagamit mo. Or maybe it's already outdated or baka improperly stored siya or baka contaminated siya. So you are going to get a new control and yun yung gagamitin mo sa machine.

If the control is still out, okay? Kahit yung bagong kinuha mo na, If the control is still out, look for and correct any problems, then run the control. So, ano yung mga possible problems?

Bakit hindi pumapasok yung control even after we change it already to a new one? So, maybe the problem is in the reagents. So, baka yung reagents mo konti na lang, outdated, improperly stored, or contaminated. Or baka yung preventive maintenance mo is already overdue. Or baka merong mechanical problem.

baka may clot dun sa specimen or baka dun sa loob ng machine, for example. So, resulting to the failure of making the control fall within the range. So, if the control is still out, even after you already check for all those possible sources of error, then you recalibrate the machine and then you run the control. Okay? So, Maybe the reason why the control will not enter is because the calibration on the first place is erroneous.

Next, if the control is still out even after you recalibrated the machine, then you get assistance. So, we know that our machines are sometimes tied up with companies. So, usually, we call their services, their engineers. pumunta sa laboratory in order to check the machine.

And once the problem is resolved, then it has to be documented. And yung corrective action na ginawa doon has to be documented also. So this will provide a record for future reference and to determine and avoid the same problem from happening again.

And lastly, you evaluate all patient results during the rejected run. and compare it with the last run with acceptable quality control. And repeat the tests and issue corrected reports as needed. Because of course, the first one, most likely, our results are really erroneous. So we have to repeat sample testing again.

Because again, we are obliged to be able to release reliable results to our patients. So far, that's all for our quality control concepts. Okay, so let us now proceed to diagnostic efficacy or efficiency. So, itong mga values na ito, they are usually present sa mga ginagamit natin na test methods.

Through these values, malalaman natin saan ba mas okay or saan mas pwedeng gamitin or mas efficient yung isang test method. whether okay ba siyang gamitin na screening method or confirmatory method. And again, that is based on its sensitivity, specificity, positive predictive value, and negative predictive value. I think for this, yung pinaka-importante is marunong tayong mag-solve ng mga values na ito. So when we say diagnostic sensitivity, this is the ability of a test to detect disease and is expressed as the proportion of persons with disease in whom the test is positive.

So in simple terms, when we say diagnostic sensitivity, kung baga sa lahat ng taong may sakit, ilan ba dun yung nadidetect ng ating test method? So the formula for this is true positives over true positives. plus false negative. This is it. True positive over true positive plus false negative.

Because when we say false negative, those people have pain, but they are not detected by the test method. Okay? Times 100. When we say diagnostic specificity, This is the ability to detect the absence of disease. So, kung baga, sa lahat ng mga taong walang sakit or normal, ilan ba dun yung nabibigyan ng tamang negative result ng ating test method? So, the formula for this is true negative.

over true negative plus false positive times 100. So they are expressed in percent. Now be careful with the formula of PPV or positive predictive value kasi halos magkamukha siya with the diagnostic sensitivity formula. So ito naman, this is true positive over true positive plus false positive times 100%. So pag sinabi natin, Positive predictive value, this is the chance of an individual having a given disease or condition if the test is abnormal.

So, kung baga, sa lahat ng positive result na nire-release or sa lahat ng positive result ng isang test method, ilan ba dun yung tama or ilan ba dun yung tunay na positive? So that means if the positive predictive value of a test method is high, that means most likely, tama yung nabibigay niya na positive result. So in contrast, pag sinabi naman natin na negative predictive value, kung baga sa lahat ng negative results ng isang test or ng isang method, ilan ba dun yung tunay na negative?

So that is true negative over true negative plus false negative times 100. Okay? So, So... Again, sa sinabi ko kanina, na dito natin malalaman kung saan ba mas okay na gamitin yung isang method. Whether it is to be used as a screening test or as a confirmatory test.

So ito lang yung tatandaan natin. If the method is sensitive, usually ginagamit yan sila as a screening test. So sensitive methods are utilized as a screening test.

Bakit? The purpose of this is because we do not want to miss a case. We do not want to miss a case.

So that means, pag yung isang method ay sensitive, we want to decrease the false negative results. We want to decrease the false negative results. Ayaw natin na mamiss natin na yung isang tao may sakit.

pero hindi siya na-detect ng method. However, sometimes because of the sensitivity of a test method, pag masyado siyang sensitive, tumataas yung false positive values. Ito naman yung nagiging disadvantage niya.

Tumataas yung mga false positive na value. Kasi sobrang sensitive ng method. Kahit walang sakit yung tao, na bibigyan siya ng positive result. But it's fine. Kasi yung mga screening test, nasusundan niya ng mas specific na method.

So, yung mga ginagamit naman, na confirmatory test, they have to be specific. They have to be specific. Why?

Because we do not want to misdiagnose a person. So, with the use of specific test, kumbaga, bumaba ba yung chances of giving a false positive result? Okay?

Ayaw natin na mabigyan natin ng positive result yung isang taong walang sakit. Okay? However, if the method is too specific, sobrang specific niya, sometimes, namimiss natin, okay, yung pag-detect ng sakit talaga ng tao.

So, tumataas, yung chances of having false negative results. Okay? Hindi natin nadidetect na ay itong taong palang, itong taong ito pala ay may sakit talaga kasi sobrang specific ng test method. Okay?

So yan yung pagkakasunod-sunod ng testing natin. We are starting with a screening test with a higher sensitivity and yung mga confirmatory tests have to be very specific. Because again, bakit kailangan sensitive yung mga screening test? Because we do not want to miss a case.

Okay? And bakit kailangan specific yung mga confirmatory test? Because we do not want to misdiagnose a person. So ako, yung palatandaan ko dito, tinatandaan ko dito yung N.

Ito, tatandaan mo yung N. Okay? Sensitive, binababa niya yung false negative result. Specific P, binababa niya yung false positive results. Okay?

So next, let's proceed to laboratory mathematics. From time to time, may mga tanong when it comes to... So here we have proportionally equivalent solution and we have delusion equations.

Paano natin malalaman if the problem is a proportionally equivalent problem or if the problem is a delusion problem? Pag proportionally equivalent problem, there is no change in concentration. Take note natin dito that there is no change.

There is no change. in concentration. Okay? And pag sinabi naman nating delusion equation, syempre pag nag-dedelute tayo, habang tumataas yung delusion, bumababa yung concentration.

Diba? So, ibig sabihin, there is change. Okay?

In concentration dito. Okay? Change in concentration.

So, Malalaman natin yan. Take note natin yung mga relationships na ito. Habang tumataas yung dilution, take note natin na tumataas yung kanyang volume. Kasi pag nagdadagdag tayo ng diluent, siyempre tumataas yung volume ng solution. And yung concentration ng solution bumababa.

Bumababa yung concentration ng solution. So, pag yung isang problem ay proportionally equivalent problem, ano yung magiging formula natin for that? So, that would be weight 1 over V1 is equal to weight 2 over V2.

Weight 1 over V1 is equal to weight 2 over V2. Pag sinabi naman natin na delusion equation, yan yung C1V1 is equal to C2V2. So, I'll give you a problem here so we can have an example on this type of problems. So, for example, problems of proportionally equivalent solutions.

So, for example, this. So let's say if a 5.0 DL deciliter solution contains 4.5 milligrams of bilirubin, how much? How much bilirubin would there be in a 2.0 DL solution? Kung yung 5.0 deciliter daw na solution ay may lamang 4.5 milligrams ng bilirubin, ilan yung laman na bilirubin if kukuha tayo ng 2.0 deciliter ng kaparehong solution? So there is no change in concentration here because we are talking about the same solution.

It's just that we are getting an aliquot or a certain value of the entire solution. So again, the formula for this is weight 1 over V1 is equal to weight 2 over So, simple lang naman yan. If yung weight 1 natin is 4.5, kung merong 4.5 milligrams na bilirubin sa 5.0 DL na solution, ilan daw yung bilirubin, that's our weight 2, sa 2.0 deciliter na alikot of the same solution.

So, syempre, ikukross multiply lang naman natin yan. Ito yung magiging simplified. Iko cross multiply mo. Diba ganyan? Okay?

So ito yung magiging simplified equation. So weight 2 is equal to 4.5 milligrams times 2.0 deciliter over 5.0 deciliter. So cancel natin yung unit na yan.

Okay, so 4.5 times 2. That's 9 milligrams divided by 5.0. So I think that would give you 1.8 milligrams of bilirubin. Okay, 1.8 milligrams of bilirubin.

So that means kung sa 5.0 deciliter may 4.5 milligrams na bilirubin, sa 2.0 deciliter merong 1.8 milligrams na bilirubin. Okay, so that's an example of a proportionally equivalent solution or equation. Now, pag-dilution naman yung problem, ito.

Another example. So, okay, what volume of a 0.5 molar glucose solution It can be made from a 100 ml of a 3 molar glucose stock solution. So, meron tayong 3 molar. na glucose solution, meron tayong 100 ml na 3 molar glucose solution. Ididelute natin ito para makagawa tayo ng 0.5 molar.

So ilang ml ng 0.5 molar glucose solution yung magagawa natin. So dito pa lang sa problem, makikita natin that there is a difference in the concentration. Yung stock solution natin, 3 molar yung kanyang concentration. Then we will make a solution that the concentration is 0.5 molar.

So if you would notice, the concentration will be low when we dilute a solution. So our formula here is C1V1 is equal to C2V2. C1V1 is equal to C2V2. So our C1, our concentration 1, let's say 3 molar times Young Volume 1 is 100 ml. Concentration 2 is 0.5 molar times V2.

The simplified formula is to divide both sides by 0.5. Divide both sides by 0.5 molar. So that would be V2 is equal to 3 molar times 100 ml over 0.5 molar.

Okay? So, eliminate natin yung unit na yan. So, that would be 3 times 100. So, that's 600. 3 times 100, rather, is 300 ml divided by 0.5. So, yung volume 2 natin is 600 ml.

Okay? So, namemaintain natin yung relationship na sinasabi ko kanina that when we dilute a solution, tumataas yung kanyang concentration. yung unang concentration natin, 100 ml, the resulting concentration is 600 ml.

So, tumaas yung kanyang volume, bumaba yung kanyang concentration. From a 3 molar concentration, naging 0.5 molar concentration siya. Okay? So, kailangan lang natin i-analyze na mabuti yung tanong whether it's proportionally equivalent or a dilution equation. Okay?

And of course, Huwag kalimutan yung ratio tsaka delusion. Okay? So, napakarami ng recall, no?

Napakarami ng delusion problems na lumabas sa ASAP exam. So, ano ba yung pinagkaiba ng dalawa? So, pag sinabi natin na ratio, it's an expression of one part of something, a part of something, per part or per whole. So, Usually, ginagamit natin ito to describe a solute and a solvent or a solute or a solution.

So, ito, bigyan ko kayo ng example para masimple. Let's say, nagmix tayo ng 1 ml ng serum plus 4 ml ng saline. So, ano ba yung mga ratios na pwede nating ma-derive from this mixture na ginawa natin? So, pwede tayong talungin, ano yung ratio?

ng serum to saline. So that would be 1 is to 4. Pwede tayong tanungin, ano yung ratio ng serum to the total volume of the solution. So that would be 1 is 2, the total volume is 5. You can also reverse it.

What is the ratio of saline to serum? What is the ratio of saline to the total solution? What is the ratio of saline to the total solution?

You can do that. So it's anything, right? Saline to solution, so that would be 4 is to 5. So that's the ratio.

Now, pag sinabi naman natin na dilution, dilution is volume of the solute over the total volume of the solution. So if gagamitin natin yung kaparehong example, our solute here is the serum. Yan yung dinidisolve.

So that's 1 and the total volume is 5. So our dilution is 1 over 5. Now, ginagawa natin minsan yung dilution, let's say for example, pag masyadong mataas yung value ng analyte na hindi na kayang imeasure linearly ng ating machine, kailangan natin idilute yung ating serum in order to decrease the concentration of the analyte to a value that is measurable by our machine. Okay? So, since dinilute natin yung serum, whatever the result of the machine, that is not the true value. That is the diluted value. So in order for us to solve for the actual value, we need to multiply it to the so-called dilution factor.

And simply, when we say dilution factor, dilution factor is simply the reciprocal of dilution. So if your dilution is 1 over 5, your dilution factor is 5. I'll give you a recall question on ASCP when it comes to dilution. Maka ilang beses na lumabas yung tanong na to. Nagkaroon daw ng flagging sa machine. Diba?

Ganoon naman talaga yung nangyayari. Pag masyadong mataas yung concentration ng isang analyte, nagfa-flag yung machine. So, since nag-flag yung machine, yung ginawa ng MedTech is nag-dilute siya by mixing by mixing 0.1 ml of a serum plus 1.9 ml of the diluent.

Now, after he did this dilution, he measured the dilution. If I could correctly recall, the measure he measured in the recall question is the LDH value. So nagkaroon daw ng flagging, kaya siya nag-dilute. So after doing the dilution, yung kanyang diluted sample, yun yung ginamit niya na sample dun sa testing. But still, nagkaroon pa rin ang flagging.

So ibig sabihin, kahit nag-dilute na siya, yung concentration dun sa diluted sample is still very high that it cannot be measured by the machine properly. So yung ginawa ng MedTech, gumawa siya ng another dilution. So yung una niyang dinilute, dinilute niya ulit.

Okay? So yung ginawa naman niya is, if I could correctly recall, parang 2 ml, no? 2 ml of the diluted sample. Yung dinilute niya na kanina, dinilute niya pa ulit.

So 2 ml of the diluted sample, okay, plus 3 ml. of the diluent. So dito makikita natin na yung ating serum was diluted twice. So this is an example of a compound dilution.

This is an example of a compound dilution. Pag simple dilution, isang beses ka lang nag-dilute. Pag sinabing compound dilution, you diluted the sample several times and you are not using consistent volumes. Because earlier, 0.1 is to 1.9. Now, what he used is 2 is to 3. So, it's not consistent with the volume that he uses.

Because if you are consistent with the volumes that you are using, that is an example of a serial delusion. What we see in antibody titer or in MIC, when we dilute an antibiotic, it's a serial delusion. Because we are consistent with the volumes that we use.

Ito, hindi tayo consistent. So this is an example of a compound delusion. So how do we get the final delusion in this case?

All you have to do is to multiply all of the delusions made. Okay? So yung unang delusion na ginawa niya, ito.

ano ba yung dilution natin dito? So this is 0.1 over, that's the volume of the solute, 0.1 ml, over our total volume is 2.0. 1.9 plus 0.1.

So this is our first dilution. We could simplify this as to 1 over 20. Diba? Yung ginawa ko, minultiply ko to by 10, minultiply ko din to by 10. So our first dilution is 1 over 20. Now, ano yung pangalawang dilution natin?

That is 2 over the total volume is 5. Okay? So this is our second dilution. So for us to get our final, okay?

For us to get our final dilution, all we have to do is to multiply the two dilutions. So that's 1 over 20 times 2 over 5. Okay? So that's 1 times 2. That's 2 over 20 times 5. That's 100. So we could simplify this. Pwede siyang maging 1 over 50. So this is now our final dilution.

Now, nung minasure daw natin yung diluted, yung finally diluted sample, yung LBH value daw, yung LBH value sa pinakahuling dilution is 120 international units. Yung tanong dun sa exam was, ano daw yung actual? Or what is the value that you will report?

What is the actual value or reported value? Of course, you cannot report 120 international units because that is not the actual value of the patient sample. Because 120 international units, that is the diluted value. So for us to get the actual value or the reported value, all we have to do is to multiply the diluted value times our dilution factor.

So ano yung dilution factor natin? Ito. Okay? Reciprocal, diba?

So yung baliktad. So 50 over 1, that's 50. Okay? So 120 times 50, which is our dilution factor, that would give us 6,000 international units. So this is our reported value. So yan po yung example ng problem sa dilution.

Okay? So, next is, of course, yung ating analytical techniques. So, syempre, huwag na huwag kalimutan yung spectrophotometer. Medyo basic ito, pero may mga recall questions pa din when it comes to the spectro. So, here's the basic configuration of our spectrophotometer.

So, we have here our light source. So this is our light source So it provides polychromatophilic Or polychromatic rather Light And it must generate sufficient energy To measure the analyte of interest So this is our light source So our light source Differ depending on What will be Our spectrophotometric work If we are to use UV Infrared or Visible spectrum So usually, pag visible, yung pinaka ginagamit natin dito is the tungsten. Okay?

The tungsten filament na lamp. Okay? The tungsten lamp.

Next, we have here our entrance slit. So the purpose of the entrance slit, okay, is to minimize stray light. Okay? And prevent the entrance of scattered light into the monochromator system.

Okay? So, ito yung naging recall question sa exam. Yung tinatawag natin na monochromator.

Okay? Yung monochromator, tinatawag din yan siya na wavelength selector because it isolates the specific wavelength needed for the measurement. I'm sure you could relate kasi for example, if we want to measure, let's say, bilirubin, kailangan natin 450 nanometers.

If we want to perform, let's say, the biuret technique sa protein determination, on. 560 nanometers yung ginagamit natin dun. So, kabaho yan ng ating monochromator or ng ating wavelength selector to select the wavelength needed for the measurement.

Okay? So, ito, no? This is our monochromator system.

Okay? Next is, ito. This is our exit slit.

Okay? So, that is the exit slit. So, the purpose of the exit slit is to allow only a narrow fraction of light to reach the qubit. Okay? Cubette.

So this is our cubette. So it holds the solution whose concentration is to be measured. So it's also called a sample holder. Okay?

Next, we have our photo detector. Okay? The photo detector. So this is it.

So usually, the photo detector is also there, the so-called signal processor. Because the photo detector... dinidetect niya yung transmitted light. So this is the transmitted light. Dinidetect niya yan and kinoconvert niya yan into a photoelectric energy.

In order for us to generate a numerical value from it. And that numerical value is being displayed sa tinatawag natin na read-out device. So yung read-out device na yan, pwede siyang LED display.

It could be the computer monitor. Ito yung ating... Read-out device. So that's the basic configuration of our spectrophotometer. So for the quality control of the spectrophotometer, may dalawang terms ako na I want you to really remember.

First, yung tinatawag natin na wavelength accuracy. Ano ba ibig sabihin ito? Okay, wavelength accuracy. So it implies that a photometer or a spectrophotometer is measuring at the wavelength that it is set to.

So this can be assessed easily using special glass-type optical filters. So this wavelength accuracy, it tells us about the function of our monochromator. If we set it to isolate, let's say, 450 nanometer, it really isolates the wavelength. So that's what we meant by wavelength accuracy. So, ano yung mga examples ng glass-type optical filters na ito na pwede natin gamitin in order to assess if our spectrophotometer has wavelength accuracy?

So, pwede tayong gumamit ng tinatawag na didymium filter and pwede tayong gumamit ng homeom oxide filter. So, take note lang ng pan- pinagkaiba ng dalawa, yung didymium filter, it has a broad absorption peak. It has a broad absorption peak. So usually, this is at 600 nanometers.

Whereas, yung homeium oxide filter naman, meron siyang multiple, okay, multiple sharp, okay, absorption peaks, okay? Multiple sharp absorption peaks. And usually, this is at 360 nanometers, okay?

Next is defined as the ability of a photometric system to yield a linear relationship between the radian power incident upon its detector and the concentration of the solution being measured. Yan naman yung tinatawag natin na wavelength linearity. Ibig sabihin ito, pag sinabi natin na wavelength linearity, kumbaga, ito yung nagbibigay sa atin ng parang assurance na whatever the result that is given out by our spectrophotometer, it really represents the amount of absorbing substances doon sa ating solution.

So that is wavelength linearity. And I've included here selected analytical techniques. So, please take note because I'll mention because a number of these also came out in my exam.

Very simple lang naman yung tanong. Nagbibigay sila na parang analyte and ano daw yung technique na ginagamit. So first, I don't know.

Bakit ko pa in-include dito? This one is an obsolete technique already, yung tinatawag natin na flame emission photometry. Flame emission photometry.

So this one measures light emitted by easily excited atoms. So yung nangyayari dito, with the use of heat or radiant energy, na-excite natin yung mga atoms. And when they are excited, they are releasing light.

They are releasing energy. So, syempre, the color of the light, or the... In the case of flame emission photometry, kasi nag-change yung kulay ng flame.

And the color of the flame changes depending on the substance being measured. That's why meron tayong sodium yellow, potassium violet, calcium red-orange, magnesium blue, mga ganyan. And the intensity of the color is depending on the concentration of the substance being measured. So just take note, the internal standards used here are lithium and cesium. But FEP is already obsolete.

Now, this one measures light absorbed by ground state atom. So when we say ground state, it means unexcited. That's why this method is used for analytes that are not easily excited by the flame. Yung mga hindi mabilis na e-excite, minimeasure na lang sila sa kanilang ground state. Yan yung tinatawag natin na atomic absorption spectrophotometry.

Atomic absorption spectrophotometry. So example guys of analytes that are not easily excited are calcium and... magnesium.

Calcium and magnesium. So, take note, recall question, take note yung ating hollow cathode lamp. Yung hollow cathode lamp, kasi ito yung ginagamit natin na light source sa AAS.

This is the light source for atomic absorption spectrophotometry. Next, atoms absorb light of a specific wavelength. and emit light of a longer wavelength. This is a recall question. Yung nandun is binigay yung definition ng method, tapos pina-identify kung anong method siya.

So that is fluorometry. Okay? Fluorometry.

So take note guys, na isa sa mga tatandaan natin na characteristic ng fluorometry is that it is sensitive and specific. Okay? Sensitive and specific. Next. Measures the reduction in light transmission by particles in suspension.

So usually ginagamit ito to measure proteins in urine and CSF. We have turbidimetry. Turbidimetry.

And measures light at an angle from light source. Usually for the measurement of antigen-antibody reactions, this is nephelometry. Nephelometry. So yung pinagkaiba ng dalawa is the positioning of the photodetector. So for example, if this is your light source, let's say this is your light source, and this is the sample holder, pag sinabi nating turbidimetry, ito yung kanyang photodetector.

Pag sinabi nating nephelometry, ito yung kanyang photodetector. The photodetector is positioned at an angle. Kasi sa turbidimetry, kumbaga, minimesure mo yung light na nabablock ng solution. Pag sinabi nating nephelometry, minimeasure natin yung light na sinascatter ng solution. That's why the photodetector is positioned at an angle.

Okay? Next, ito yung lumabas aking exam. Very simple yung tanong. Ano daw yung principle na ginagamit sa pH determination? So that is potentiometry.

Okay? Potentiometry. So ito din yung principle sa tinatawag natin guys na ion selective electrode.

Okay? ion, selective electrode. Okay? So for pH and PCO2 determination, so that is potentiometry.

Ito yung lumabas sa akin. Principle for pH determination. Next, this is used for measurement naman of PO2. Okay?

So it measures current flow produced by oxidation reaction. So ito yung tinatawag natin na amperometry. Okay? Amperometry.

Or tinatawag din siya na polarography. Okay? Polarography. So ginagamit siya for PO2 determination.

Diba? May electrode tayo for PO2. Yung tawag natin doon is the Clark electrode. Yan. So PO2 determination, amperometry.

Pag pH and PCO2 determination, potentiometry naman yun. Kung Clark electrode yung ginagamit for PO2, yung ginagamit sa PCO2 naman is the severing house electrode. Okay? Severing house electrode. Tapos for pH determination, glass electrode lang yan.

Okay? Next, involves measurement of the quantity of electricity needed to convert an analyte to a different oxidation state. Ginagamit siya usually to measure chloride ions, might it be in the serum, the plasma, the CSF, or sweat samples. Ito yung collometry. And lastly, involves measurement of the resulting current after a potential is applied to an electrochemical cell.

Usually, ginagamit siya to measure heavy metals. Example of this is... The measurement of lead, yung tinatawag natin na voltammetry.

Okay? So, yan po for our selected analytical techniques. Okay?

So, pakite-take note lang ng mga nilalagyan ko ng star, ng mga recall question. So, so far, that's all for our topics on laboratory operations. Thank you.

Transcript for:Laboratory Operations and Quality Management

Transcript for:
Laboratory Operations and Quality Management