DNA sample buffer

Question

Gel loading buffer contains 20% glycerol. What effect do you think this has on the density of your DNA sample? Why is this advantageous when loading samples into an agarose gel?

Answer 1

The 20% glycerol in the gel loading buffer makes the DNA sample denser. This is helpful because when we load the sample into the agarose gel, the denser sample sinks into the well instead of floating away into the buffer. This makes it easier to load the DNA properly and keeps the sample in the well until the electrophoresis starts.