Question

Agarose gel electrophoresis at high voltage and increased resistance

Answer 1

We use electrophoresis to separate nucleic acids or proteins by size and/or charge, depending on what we’ve put into our solutions (more of an issue with SDS-PAGE; see Chapter 7). Basically, in gel electrophoresis, you put your samples into a gel matrix and your negatively charged nucleic acids (negatively charged due to their phosphate “backbone”) are repelled from the negative pole of your electrodes and toward the positive pole at the other end of the gel. Larger RNAs and DNAs (and proteins, in SDS-PAGE) have a harder time moving through the gel matrix and therefore you can separate your RNA/DNA/proteins by size. Additionally, this is the only way to check your results from end-point PCR