Electrophoresis is one of the most common analytical tools in biotechnology -- where very large molecules must be separated.

During electrophoresis, a buffer controls the charge on the large ions while a very large voltage is applied.

In the most common electrophoretic procedures, samples are applied to a gel that acts as a stationary phase. An applied voltage then pulls the charged molecules in the sample through the gel. The gel interacts with the components of the sample separating the parts. The gel is frequently cooled to minimize both eddy currents and broadening from heating. The gel is stained and absorptions can be measured.

Electrophoresis is used for both large protein and nucleic acid separations.

What is electrophoresis? Gel electrophoresis.