Final answer:
After electrophoresis, the gel should be soaked in a solution that can depurinate DNA. One common depurination solution is 0.25 M HCl. This process helps to remove any remaining DNA that is not fully separated during electrophoresis.
Step-by-step explanation:
After electrophoresis, the gel should be soaked in a solution that can depurinate DNA. One common depurination solution is 0.25 M HCl. Soaking the gel in this acidic solution breaks the glycosidic bonds between the purine bases (adenine and guanine) and the sugar backbone of DNA, resulting in the removal of purines. This process helps to remove any remaining DNA that is not fully separated during electrophoresis (Figure 14.9).