Electrophoresis

The sample is loaded into a gel matrix support. This has many important advantages:

1. The density and porosity of gels can be easily controlled and adjusted for different biomolecules or different experimental conditions. Since the gel pore size is on the order of the dimensions of the macromolecules, the separations are based on molecular sieving as well as electrophoretic mobility of the molecules. Large molecules are retarded relative to smaller molecules as they cannot pass as easily through the gel during electrophoresis.
2. Gels are easy to chemically modify, for related techniques such as affinity electrophoresis which separates biomolecules on the basis of biomolecular affinity or recognition.
3. Excellent separation power.