Electrophoresis is used particularly in medicine and biology and provides information about the composition of mixtures. The term refers to the movement of electrically charged particles through a substance in an electric field. This substance acts as a carrier material. 

In gel electrophoresis, the relationship between the particle radius and the pore size of the gel serving as the carrier medium interacts. As this gel acts as a molecular sieve, a larger particle radius has a greater inhibitory effect on the migration speed than viscosity alone. Due to the different ionic charge and particle radius, the individual molecules therefore move through the carrier material at different speeds and achieve separation according to their electrophoretic mobility. For this reason, electrophoresis is particularly suitable for separating mixtures of substances, especially mixtures of molecules such as blood. Liquids, gels or solids can be used as the carrier material. Electrophoresis therefore makes it possible to separate and identify molecules of different lengths and sizes.