Post-Thanksgiving

Another thanksgiving break has come and gone. And to think it's the last one I'll have as an undergrad. It was a nice break, with lots of good food (though too much sugary stuff). I did homework, of course (I had too much not to), but it was at a relatively leisurely pace. I didn't sit around like a bum and do nothing, but it was definitely relaxing, despite having work to do. And even though I didn't finish anything, I don't feel particularly stressed by due dates right now. Though I completely forgot about both the biochem take home test and the lab poster. But it's still not going to be anything like the two weeks before break were. Those were nuts.

So biochem lab today was...surprising. We were supposed to test the inhibition of tyrosinase with a water based sunscreen. Well, the sunscreen was lotion, and even though it was water based, it wasn't water soluble. The cuvette was very cloudy when the sunscreen was added, and we spent over an hour testing different concentrations and lamenting our "failed" experimental design. Meg came up with an "apple assay" idea that we could do as an alternative (slice up an apple and apply sunscreen, comparing it to various controls), and Dr. Kuhlman suggested that if we let the cuvettes sit for 3 minutes, centrifuge them, and then take an absorbance value we could still get a line (albeit with only two points, as opposed to the data-point-every-5-seconds-for-3-minutes line we would get taking the reaction rate progress like we did for thiourea). So with two sort of shaky ideas, we decided to do them both and compare them. And while neither worked as well as we would have liked, the results were consistent between the two, and they were NOT what we expected! Basically, one of the ingredients in the sunscreen was a tyrosinase inhibitor (which is the reason we tested it in the first place). The sunscreen seemed to ENHANCE tyrosinase activity for both the apple assay and the more quantitative enzyme assay. So my theory is that one of the ingredients is a tyrosinase enhancer, and its effect is stronger than the inhibition, and essentially this would allow people to tan more quickly while still being protected from UV radiation. We just don't know if there is such an ingredient in this product. But essentially we now have interesting results from two creative experiments, when we thought that we'd have nothing. And our poster should end up being cool.

I should probably mention that I FINISHED MY SENIOR RESEARCH!!!! Turned the three copies in on Monday, and now I don't have to worry about it anymore. It'll be interesting to get the comments from my readers (Dr. Homan, Dr. Schultz, and Dr. Spieles), but for now I can focus on my remaining three classes.

And now it's bed time. I love getting to bed before midnight :)