Immunoassays are commonly used in biotechnology for the detection and quantification of host cell contaminants. The free-solution approach by CGE with fluorescence detection offers an exciting alternative to solid-phase immunoassay. It eliminates antigen immobilization and avoids many problems associated with solid phase. The methodology makes use of either a purified antigen labeled with stable fluorescent dye (i.e., FITC) or an affinity probe labeled with the dye (direct assay).
Capillary gel electrophoresis using sodium dodecyl sulfate (CE-SDS) is used commercially to provide quantitative purity data for therapeutic protein characterization and release.
