For the past week and a half, I have been doing gel electrophoresis to determine ideal concentrations of various chemicals to digest my DNA and histone proteins. Gel electrophoresis is a biological technique used to determine the size of the molecules in samples. For DNA, the technique is especially useful at determining how many base pairs a strand of DNA has. It is a mostly qualitative measurement, where samples can be compared to a known DNA ladder standard. Gel electrophoresis works by inserting samples into lanes of a gel, and applying a current through the gel and a buffer medium. Because DNA is negatively charged, it will travel towards the anode. Shorter DNA will travel faster though, because it is more easily able to maneuver through the maze-like holes in the gel.
Below is an image of the first gel I ran. The DNA ladders on the two ends are very crisp and visible – but there is a problem with the other samples; none of them moved. Such non-movement was likely because the digestions were not working. We have attempted different concentrations of our digestion chemicals, but have yet to find a solution. While we wait for more supplies to be ordered, I will begin making another sample of nucleosomes again from the 50 mL of whole chicken blood. Hopefully the gel electrophoresis problems will soon be resolved, and we won’t have this issue again in the future!