Gel electrophoresis is a technique used to separate DNA fragments (or other macromolecules, such as RNA and proteins) based on their size and charge. Electrophoresis involves running a current through a gel containing the molecules of interest. Based on their size and charge, the molecules will travel through the gel in different directions or at different speeds, allowing them to be separated from one another.
- Electrophoresis enables you to distinguish DNA fragments of different lengths.
- DNA is negatively charged, therefore, when an electric current is applied to the gel, DNA will migrate towards the positively charged electrode.
- Shorter strands of DNA move more quickly through the gel than longer strands resulting in the fragments being arranged in order of size.