Pros & Cons of Gel Electrophoresis

Gel electrophoresis is used to separate molecules based on molecular weight and charge. Deoxyribonucleic acid (DNA), ribonucleic acid (RNA) and proteins can be separated using gel electrophoresis. Agarose and polyacrylamide are the most common materials used to form the gel.

History

• Gel electrophoresis was first introduced in the 1930s. During the 1960s and 1970s, most of the techniques for separating DNA and proteins were developed.

Advantage: Detection Limits Based on Size

• Most DNA, RNA and proteins can be detected using gel electrophoresis, regardless of size. The concentration of the gel matrix is chosen beforehand to easily separate the molecule of interest based on the estimated size.

Advantage: Starting Material

• A large amount of starting material is not needed for gel electrophoresis. For example, picograms of DNA can be detected using electrophoresis.

Disadvantage: Difficult to Extract Samples

• Once a sample has been run on a gel, it is possible to extract the sample from the gel for further analysis. However, it is nearly impossible to obtain all of the material in the original sample.

Disadvantage: Harmful Materials

• Care must be taken when handling materials used in gel electrophoresis. For example, ethidium bromide is commonly used in DNA gel electrophoresis, and is a known mutagen.