Polyacrylamide gel

Polyacrylamide gel is a type of gel used in biochemistry, molecular biology, genetics, and clinical chemistry to separate biological macromolecules, usually proteins or nucleic acids, based on their physical properties.

Composition

Polyacrylamide gel is composed of acrylamide and bisacrylamide monomers that are cross-linked in order to form a mesh-like network. The ratio of acrylamide to bisacrylamide can be varied to create gels with different pore sizes, allowing for the separation of molecules of different sizes.

Use in Gel Electrophoresis

Polyacrylamide gel is most commonly used in a technique known as polyacrylamide gel electrophoresis (PAGE). In this process, a sample is loaded into a well in the gel and an electric current is applied. The molecules in the sample move through the gel at different rates depending on their size, charge, and shape, allowing them to be separated.

Variations

There are several variations of polyacrylamide gel electrophoresis, including SDS-PAGE, which uses sodium dodecyl sulfate to denature proteins and give them a negative charge, and two-dimensional gel electrophoresis, which separates proteins first by their isoelectric point and then by their size.

Safety

Polyacrylamide gel is generally safe to handle, but the acrylamide monomer is a potent neurotoxin and is potentially carcinogenic. Therefore, care must be taken when handling acrylamide powder or solutions.

See Also

• Agarose gel electrophoresis
• Capillary electrophoresis
• Isoelectric focusing