electrophoresis \electrophoresis\ n.
1. (Chem.) the motion of charged molecules or particles in a
liquid medium under the influence of an electric field;
particles with a positive charge move toward the cathode
and negative to the anode. [WordNet sense 1]
Syn: cataphoresis.
[WordNet 1.5]
2. (Chem., Biochem.) the application of the principle of
electrophoresis to separate molecules, used as an
analytical or preparative technique; as, separation by
electrophoresis; gel electrophoresis.
[PJC]
Note:
Gel electrophoresis is a technique in which the molecules
to be separated are moved through a gelatinous medium
under the influence of an electric field. At the
completion of a period of electrophoresis, the gel, unlike
a liquid solution, may be manipulated as a single object,
permitting the substances contained within to be detected
or visualized by a variety of methods, and their relative
mobilities determined. It is therefore a popular analytic
tool in biochemistry, and has many variants. Popular
substances used to create the gel are starch,
polyacrylamide, and agarose. Since a polyacrylamide gel
can be created with different concentrations and different
degrees of cross-linking, the pore size of the gel can be
controlled to provide special properties appropriate to
separation of specific molecules, as for example
optimizaion for separation within a particular molecular
weight range. in SDS-polyacrylamide gel electrophoresis,
SDS (sodium dodecyl sulfate, a detergent) is included;
it binds to and denatures protein molecules, allowing them
to be separated on the basis of their molecular weight
alone. It is thus used as one method of determining the
molecular weights of isolated protein chains.
[PJC]
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