Applied Biosystems of Foster City, Calif. has introduced the first commercially available instrument that allows scientists—biochemists, for instance—studying biomolecules to take advantage of the innovative technique of capillary electrophoresis (CE). Basically, the Model 270A CE system is an analytical tool that can separate and identify molecules by differences in charge density. CE promises to complement and, in some cases, improve upon the three standard separation techniques: liquid chromatography, ultracentrifugation, and electrophoretic techniques.

Liquid chromatography is primarily a preparative separation technique based on molecular weight or net charge; ultracentrifugation is also a preparative technique, which separates molecules by differences in sedimentation; and electrophoresis techniques provide analytical separations through isoelectric point or molecular weight. It has long been recognized that many types of molecules can be identified by differences in electrophoretic mobility, and these three techniques have provided the experimental foundation for the isolation and analysis of biomolecules.

For example, polyacrylamide gel...

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