I love teaching the Evolution lab class at Georgia. I really do. But this class has led to more sleepless nights over the past 6 years than any other; why? Because maintaining a good flow of information, education, and fun in a lab class is tricky. And while failure is a large part of science, it doesn’t play well when you have a limited number of opportunities to teach and a number of topics you want to teach.

This year GENE 4230 will be repeating Peter Marko’s 2004 work on red snappers. This paper showed that much of what we buy at the store may actually be Lutjanus campechinus; but much of it is not. Fish fillets sold at red snapper prices are sometimes other (rarer) snapper species. Sometimes they aren’t snapper at all, but less valuable fishes. And all of that ambiguity leads questions about how best to manage this threatened stock. Currently, the fishery is closed on our Atlantic coast.

The problem? When I had Kelly double-check my protocol a couple of weeks ago to make sure the PCR would work, it did not. We tried a couple of different protocols, no dice. Finally I decided I needed to jump in and check some things. Long story short? Both our original primer stock, and the last batch of red snapper DNA we had used for this lab 2-3 years ago, were heavily degraded. They had been kept in the aging freezer in the teaching lab, so Genetics department head: there is something that we need to buy this year!

I’m pleased that I could quickly figure out what went wrong, and from the gel above it looks like the lab should work just fine (in case you are wondering, those are the short ‘universal’ fragment primers on top; the CB-12 and -13 primers from Marko’s paper below). There is a little smeariness in the negative control but I also didn’t change my tips in my rush to get this done today (Saturday....and it is 75° outside and sunny). No problem with the top set of reactions, that means I’ll be sleeping much better tonight.

Tags: freezer, lab, fish