ENZYMATIC PROFILING OF IMMOBILIZED CELLS USING CZE

Baker's yeast cells (Saccharomyces cerevisiae) were immobilized on a C ZE capillary using a midcapillary frit of novel design. The frit was c onstructed using a single 50-mu m particle with ''through pores''. Cel ls trapped on the capillary were profiled using different amino acid b eta-naphthylamide-aminopeptidase substrates. These substrates were int roduced sequentially and metabolized for 1 min. After incubation the h ydrolysis products were withdrawn by electrophoresis and detected by l aser-induced fluorescence. An aminopeptidase profile was produced usin g just 500 cells. The new CZE-based method was found to have several s ignificant advantages over the older cuvette/fluorometer method.