beta-Galactosidase assay using capillary electrophoresis laser-induced fluorescence detection and resorufin-beta-D-galactopyranoside as substrate

beta-Galactosidase was incubated for 60 min with the fluorogenic substrate resorufin-beta-D-galactopyranoside, which is converted by the action of the enzyme into resorufin and galactose. A 160 pL aliquot of reaction mixture was analyzed by capillary electrophoresis utilizing laser-induced fluoresce nce detection. Based on the detection of the resorufin formed, the limit of detection of beta-galactosidase was 1.5 x 10(-15) M or 900 molecules of en zyme in a 1 mu L sample. Copyright (C) 1999 John Wiley gr Sons, Ltd.