Polyacrylamide gel electrophoresis

Polyacrylamide gel electrophoresis (PAGE) is a technique widely used in biochemistry, forensic chemistry, genetics, molecular biology and biotechnology to separate biological macromolecules, usually proteins and nucleic acids, according to their electrophoretic mobility. Electrophoretic mobility is a function of the length, conformation and charge of the molecule.

Principle

PAGE operates on the principle that smaller molecules will pass through the pores of the gel more easily than larger ones, meaning that larger molecules will migrate more slowly, causing them to separate from smaller ones. The gel acts as a sieve through which smaller particles can move easily whereas larger particles have difficulty getting through.

Procedure

The procedure begins with the preparation of a polyacrylamide gel. Samples are then loaded into wells in the gel. An electric current is applied across the gel, causing the negatively charged molecules to move towards the positive electrode. The rate at which the molecules move is inversely proportional to their size.

Applications

PAGE is used in many different fields. In biochemistry, it is used to separate proteins according to their size and charge. In genetics, it is used to separate DNA and RNA fragments by size. In molecular biology, it is used to check the quality of protein samples. In biotechnology, it is used to separate proteins and nucleic acids for further analysis.

See also

• Electrophoresis
• Agarose gel electrophoresis
• Capillary electrophoresis
• Isoelectric focusing
• Two-dimensional gel electrophoresis

References

Polyacrylamide gel electrophoresis Resources
Latest articles Most recent articles Ongoing trials	Wikipedia