In the lab I have been helping out with three different projects, with a focus on a single project looking at different frog samples. After collecting frogs in the field (there are almost 2,000 samples of frog tissues to analyze!) we returned to the lab to figure out how the different frog species are related. The end goal is to create a phylogenetic tree to see how the different species are related. Unfortunately, there are far too many samples left to analyze, so we will most likely not be apart of the final step of building the tree. Fortunately, we get to be involved in the three steps of DNA extraction, PCR, and gel electrophoresis. Our project does not necessarily have a hypothesis, we are just trying to first see how the species are related and then they will apply this to the ecology of Thailand.
This past week we extracted DNA from five frog samples (tissue), eight cat samples (blood obtained from a local veterinarian), and four snake samples (shed obtained from the Chiang Mai Zoo). The process was essentially the same for all species and involved mashing up the shed and the tissues using liquid nitrogen. We then added chemicals to aid in the separation of the DNA from the other proteins in the samples, incubated in a water bath, and centrifuged the samples collecting the DNA from the bottom. These steps were repeated three times until we finally had our DNA. We then ran the DNA in gel electrophoresis to make sure that what we had collected was in fact DNA. It turns out that the extraction process for the frog and snake samples worked perfectly, but we only obtained RNA for the cat samples. We will now have to try another method to extract the DNA for the cat samples.
I never realized how long the process of building a phylogenetic tree takes. We have so many samples, and just the DNA extraction took an entire week to complete. Our lab mates are here five days a week for hours at a time doing the same three steps day in and day out. They have a lot of patience and determination to reach the end goal and discover new things. The exciting part about our research is that new frog species have been discovered! Each day we are in the lab I try to remind myself of the end goal just like my lab mates.