BISC413 Lab 1, August 30: Collecting trips

Your biggest project this semester will be to collect a few hundred individuals of your assigned species and run allozyme gels on them. I'll tell you more about allozymes in class; the important thing to know for today's trip is that you'll look at genetic variation by running native proteins on a gel, then staining for one particular enzyme. A "native" protein is one that is folded up into its natural, functional shape. Proteins in a living organism are in their native state. After the organism dies, the proteins are oxidized, broken into smaller peptides, or unfolded, and they no longer have enzyme activity and can't be used for allozyme gels.

To keep the proteins in their native form, you will collect live organisms and either keep them alive until you come back to the lab, or you will freeze them on dry ice as soon as you collect them. Once you get back to the lab, you will put the organisms (or small parts of them) into a -20°C freezer along with some molecular sieve desiccant. The desiccant will absorb the water from the specimens even though they are frozen, and in a week or so, they'll be freeze-dried. The proteins in a freeze-dried organism are very stable, so you'll be able to collect and freeze-dry a bunch of organisms in September, then run gels on them in October and November.

Here are some general rules for collecting and handling your organisms:

In the lab

Back in the lab, freeze your organisms to kill them (if they're not already frozen). Label two microtiter plates by putting a piece of tape across the bottom two rows, then put your name, species, collection location, and collection date on the tape. Label one microtiter plate "Sample A" and the other plate "Sample B." You'll run a gel on Sample A, then if some parts of the gel don't work, you can rerun the same individuals using Sample B.

Thaw out your organisms and sort them into the microtiter plates. For small organisms, rip the organism in half and put one half in each plate. For larger organisms, cut off a small piece to put in each well, about the size of a peppercorn, and discard the rest. Write down how many individuals you have. Put the microtiter plates in a larger plastic container with some desiccant, and put it in the freezer.

Today's species

The procedures above apply to all of your organisms. For today, you'll be collecting the following. You can lock up your stuff in the lab while you're out collecting.

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