What is the purpose of a comb in gel electrophoresis?

The purpose of a comb in gel electrophoresis is to form wells in the gel. When a comb is inserted into the gel solution before it solidifies, it creates indentations that become wells. These wells are essential for loading samples, as they allow for the separation of biomolecules, such as DNA, RNA, or proteins, during the electrophoresis process. Once the gel is run, the molecules can migrate through the gel matrix under the influence of an electric field, allowing for analysis based on size or charge.

While stability and control are important aspects of an electrophoresis experiment, they are not the primary functions of the comb. Similarly, the manipulation of the electric current is achieved by other components of the electrophoresis setup, such as the power supply, rather than the comb itself. Therefore, the correct function of a comb is directly related to the formation of wells for sample loading.