Electrophoresis

Definition

The migration of charged molecules or particles through a fluid or gel matrix under the influence of an applied electric field, used to separate, characterize, or identify biological macromolecules based on size, charge, or conformation.

Etymology

From Greek ēlektron (amber, hence electricity) and phorēsis (being carried)

Example

Protein electrophoresis of hemolymph samples distinguishes cryptic species of Anopheles mosquitoes by revealing fixed differences in enzyme loci, while DNA barcoding via gel electrophoresis validates field identifications of spider specimens in biodiversity surveys.

Related Terms

• Gel electrophoresis
• SDS-PAGE
• isoelectric focusing
• DNA barcoding
• Allozyme
• zeta potential
• Hemolymph

Usage Notes

In arthropod research, electrophoresis historically powered allozyme studies for population genetics and species delimitation before DNA sequencing became dominant; it remains essential for quality control of PCR products, RNA integrity checks, and separating proteins from venom or hemolymph. The term encompasses multiple substrate formats—agarose gels for nucleic acids, polyacrylamide for proteins—each with distinct resolution limits. Specialists distinguish analytical electrophoresis (identification, quantification) from preparative electrophoresis (purification). Capillary electrophoresis and modern free-flow methods have largely replaced slab gels in high-throughput applications.