---
title: "Gel Electrophoresis — AP Bio Definition & Exam Guide"
description: "Gel electrophoresis separates DNA, RNA, or proteins by size and charge. Learn how it works, why smaller fragments travel farther, and how it shows up on the AP Bio exam."
canonical: "https://fiveable.me/ap-bio/key-terms/gel-electrophoresis"
type: "key-term"
subject: "AP Biology"
---

# Gel Electrophoresis — AP Bio Definition & Exam Guide

## Definition

A laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size.

## Related Study Guides

- [6.8 Biotechnology](/ap-bio/unit-6/biotechnology/study-guide/9xwtV4SAygOIewEHrjGK)

## Review

### Related Terms

- Agarose Gel: A type of gel used in electrophoresis that's made from seaweed. It's like the specific type of terrain on which our race (gel electrophoresis) takes place.
- DNA Ladder: This is a mixture of DNA fragments with known lengths, used as a reference during gel electrophoresis. It's like having markers along our race track to measure how far each runner has gone.
- Polyacrylamide Gel: Another type of gel used in electrophoresis for separating smaller molecules. It’s like changing the terrain from grass (agarose) to sand (polyacrylamide), making it harder for small runners to get through.