The last few weeks of my internship at Dr. Miki’s lab were incredibly eventful. Every procedure I had completed, every cell culture plate I maintained, and all of the work I had done had finally come to a head.
During the second week of July, I prepared and commenced definitive endoderm differentiation of my undifferentiated H9 cells. Because the lab I work in is focused on treatments for liver diseases, looking at how this new molecule HT4201 could affect endoderm tissue, the precursor to liver tissue, is a crucial aspect of my project. The differentiation process involves media complete with nutrients designed for growth and differentiation. I was obliged to add certain supplements in very specific concentrations throughout the 5-day process. Thus preparation beforehand included separating the basal medium and supplements into usable aliquots and storing them in the -20 degree freezer. Preparation like this is very common in our lab environment, especially because lab-mates use the same reagents. Aliquotting is a courtesy both expected and appreciated in the lab.
After a successful protein array, I performed PCR on the RNA I had isolated throughout the internship from both my H9 and definitive endoderm cells to be able to look into which genes are affected by the presence of HT4201. Using the concentrations that I measured from my RNA beforehand, I made 20 uL of cDNA from each well. I then used this cDNA for qRT-PCR (quantitative real-time PCR). The difference between PCR and qRT-PCR is that with the former the process just amplifies whatever section of DNA you place in the thermo-cycler. But with qRT-PCR, we use a set of primers that target the genes we want to observe, and the machine gives a report on which primers are being used during the process to figure out which genes have been turned off or on. The process of preparing for qRT-PCR was tedious—I was using a 384-well plate and all colorless reagents, so mistakes were easy to make. The important thing to do when making a mistake, however, is to record exactly what went wrong. This prevents any mal-interpretation and possibly fraudulent data.
These 8 weeks I spent at the USC lab were more eventful than my experience last summer. In fact, this year’s internship felt like an extension of last year’s. Since I needed no training, I was able to go directly into my work for the summer. My PI also trusted me with more important projects, like culturing cells for other lab-mates or running an extremely delicate protein array. However, even though I shadowed and learned my techniques last year, I never stopped learning new things during these past 8 weeks. I found that learning by experience is one of the most effective methods for me personally, and that mistakes are part of the process. My PI never discouraged me by being disappointed in any way, and because of his positive attitude the entire lab strived to be the best we could be without being told. I will undoubtedly be using these learning techniques in any field I enter later on in my life. I feel very fortunate to have been able to spend my summer learning and working with such a talented and dedicated team.