hi there biology student here's the equipment and procedure for this week's lab about diffusion and membranes when you arrive in lab you'll have the following equipment a conductivity probe a rinse Beaker and rinse bottle filled with deionized water use this to clean the probe between uses you'll have a 600ml beaker and stir station a glass dish to use for soaking the strips of membrane tubing scissors and a ruler for cutting the membrane to the correct length here is some dry uncut tubing two tubing clamps to close the ends of the tubing when making your artificial cells and a 10ml graduated cylinder and dropper to measure the amount of liquid to be placed in your cell first locate the deionized or di water tap in your lab you will use only di water for this investigation measure the correct length of p32 membrane tubing and cut off two strips of similar lengths place the dry tubing in the dish filled with di water and allow it to soak for about 5 minutes fill the 600ml beaker with di water and place it on the stir station drop in a magnetic stir bar and turn the stir station to its lowest setting oh that's who that's too fast better turn it down the lowest setting is the speed at which the stir bar just begins to spin that looks good have a teammate use the 10ml graduated cylinder to retrieve the test solution from the flasks on the back lab bench use the dropper in each flask to fill your graduated cylinder be sure to keep track of which solution you're testing once the tubing has softened remove it from the water and clamp one end next rub the other end of the tubing between your thumb and index finger to force it open when the tubing has opened use the dropper to transfer the test liquid from your graduated cylinder into the tubing cell when you filled the tubing clamp the top closed hold the cell over the rinse beer and use the DI bottle to rinse any spilled test solution off of the outside of the cell this is a fully assembled artificial cell and now it's ready for testing set up your sampling regime on the computer using logger pro software and then place the conductivity probe in the beaker be careful not to disturb the spinning stir bar next carefully place your rinsed cell into the beaker so that it is fully submerged as soon as you do this have a teammate begin recording data with the logger pro software when you're trial is complete remove the Beaker from The Stir station remove and rinse the conductivity probe with di water and store the probe in the rinse Beaker between uses remove the cell and unfasten the clamps and then empty the contents of the cell back into the beaker use your fingers or a stir bar retriever to then remove the stir bar be sure to keep track of the clamps and stirb bar for future use finally take the beaker to the sink pour it out and rinse it with di water