Separation of amino acid homopolymers by capillary gel electrophoresis

Gel-filled capillaries utilizing highly concentrated and moderately cross-linked acrylamide-type gels in capillary electrophoresis were successfully applied to the separation of the individual oligomers of various poly(amino acids). Mixtures of both anionic and cationic nature were adequately resolved. While UV detection at 220 nm was mostly utilized, the polyanions with N-terminal groups can also be tagged with 3-(4-carboxybenzoyl)-2-quinolinecarboxaldehyde (CBQCA) for a more sensitive detection by a laser-induced fluorescence detector.