Hi I'm Ben Benson from the Sanford Promise
community lab at Sanford Research I'm here to share with you tips on the proper use of a
micropipette this piece of equipment is commonly used in the biomedical science research lab and we
want to make sure you can use it with confidence by mastering a few simple techniques you will have
an important new lab tool and your accuracy will increase but before you can get started there
are a couple of important first steps to take first before working in a lab you must be sure to
wear your personal protective equipment PPE choose PPE appropriate to the hazards you are working
with next look at your lab space in addition to PPE it is important to set up your lab space so
that all samples and containers are within your arm's reach also clean your space and clear it of
unnecessary items make sure you have appropriate waste containers for your used tips and arrange
your workstation so you don't have to reach over your samples being able to recognize the parts of
the pipette is important this is a commonly used pipette brand at Sanford Research the pipette
you use may be a different brand and may look slightly different but it should have these
basic parts the plunger press the plunger to pick up and dispense liquid the ejector button
press the eject button to release the used tip the tip holder is where the disposable pipette tip
attaches the volume adjustment turn this knob to set the desired volume volume indicator displays
the volume of the liquid you will be transferring pipettes are used along with plastic disposable
pipette tips to measure or transfer small amounts of liquid usually from point 2 microliters
to 1000 microliters or one milliliter the range of volume and individual pipette measures is
typically printed on the handle the volume of the pipette can be adjusted by rotating the volume
adjust knob to the desired volume remember the dial numbers indicate different volumes depending
upon which pipette is used you should never use a pipette to measure volumes outside of its intended
range doing so can cause inaccurate measurements and will damage the internal mechanisms of the
pipette there is a hook on the backside of the pipette place the hook over your pointer finger
if properly held your hand should look like a fist around the pipette and you should be able to
reach and depress the plunger and eject buttons with your thumb there are two stops on the pipette
a gentle press like a pen click it brings you to the first stop pushing harder or further like
the thumb war should get you to the second stop make sure that when you are filling the pipette
you use only the first stop this measures the liquid the second stop allows a small burst of air
behind the liquid to ensure that the liquid was expelled from the tip to keep your micropipette
from being contaminated by liquids and to measure appropriate volumes you will need a disposable
pipette tip tips are inexpensive and different size and brand to fit your micropipette once you
set your pipette to the volume needed attach the appropriate pipette tip to the end of the pipette
to do this hold the pipette with one hand aim into the opening in the tip and gently but firmly push
the pipette into the pipette tip tip should be arranged in a tip box you should not have to slam
the tip into the end of the pipette the tip only needs to be on far enough so that it doesn't fall
off to use the pipette depress the plunger to the first stop keep the plunger at this level submerge
the tip just past the level of liquid you want to draw up slowly release the plunger allowing it to
return to its original position pause for a second to make sure all the required volume has been
taken into the tip this is especially important when pipetting more viscous or thicker materials
withdraw the pipette tip from the liquid position the tip inside the recipient container and slowly
depress the plunger this will release the liquid this time push beyond the first stop to the second
stop this ensures any residual liquid is expelled from the pipette tip fully withdraw the pipette
tip from the liquid before you release the plunger use a new pipette tip with each new liquid if the
tip touches any surface or liquid other than the one you are pipetting discarded and get a new
one once you are finished pipetting dispose of your tip by aiming the base of the pipette over
the waste container and depressing the eject button this should eject the tip from the pipette
into the container if you think your tip may be contaminated remember the promise labs easy rule
for tips when in doubt throw it out let's review what we've learned to use a pipette depress the
push button until you feel some resistance this is the first stop place the pipette into the
liquid and slowly release the button to release the liquid from the pipette push past the first
stop to fully expel the liquid from the pipette tip into the recipient container before you
release the push button withdraw the pipette from the container once you have aspirated the
liquid press down on the tip ejector to release the pipette tip from the pipette the tip ejector
is a small button at the bottom of the main body of the pipette make sure the attached pipette tip
is inside the appropriate waste container before pressing the eject button now let's take a look
at a few things not to do or bloopers first do not press down before putting the tip into the
liquid this helps to avoid bubbles when putting the tip on the pipette do not slam your tip onto
the table this ruins the bottom of the tip plus it introduces unwanted contamination do not use a
pipette that does not have a tip attached liquids should never enter the body of the pipette it will
cause pipette corrosion and be a major source of contamination do not use a pipette past the volume
limits listed on the handle not only does this cause inaccuracies but also damages the pipette
sometimes you may struggle to attach a tip to a pipette if so do not repeatedly Jam the pipette
into the tip this can damage the pipette and if your tip doesn't stay on the end of the pipette
simply repeat the proper procedure with a new tip when taking up liquids do not simply let go of the
push-button the liquid may be sprayed around the inside walls of the tip and up into the pipette
body this can cause inaccurate volume dispensing and pipette contamination release the push button
in a controlled way do not slam the plunger down to move the liquid to a new container this will
spray out too strong when you are using a filter check the tip fit and the rules by following
these do's and steering clear of the bloopers you will stay safe and keep your equipment
in top shape and see your lab accuracy grow