What principle does electrophoresis operate on?

Electrophoresis operates on the principle of separating charged particles in a fluid or gel matrix under the influence of an electric field. This technique relies on both the size and the charge of the molecules being analyzed. When an electric field is applied, charged molecules will migrate towards the electrode with the opposite charge. Smaller molecules can move more easily through the gel compared to larger ones, affecting their movement speed and therefore enabling separation. The combination of size and charge allows electrophoresis to effectively separate various biomolecules, such as proteins and nucleic acids, which has wide applications in biochemistry and molecular biology.

In contrast, separation based on temperature, molecular weight only, or color does not accurately capture the operational principle behind electrophoresis, as this technique specifically utilizes the relationship between charge and size in an electric field to achieve its separations.