Ace the 2026 AALAS LATG Exam – Unlock Your Lab Animal Expertise Today!

Electrophoresis separates DNA fragments by size as they move through a gel under an electric field. DNA is negatively charged, so when voltage is applied, fragments migrate toward the positive end. The gel’s porous matrix slows larger pieces more than smaller ones, causing smaller fragments to travel faster. This allows you to estimate fragment sizes and compare samples, which is essential after PCR or restriction enzyme digests and before further analyses like sequencing or cloning. It isn’t used to cut DNA (that’s the job of restriction enzymes), clone DNA (that involves replication in a host cell), or repair DNA (that uses repair enzymes and pathways).