title: Fluorescence-based enzymatic assay by capillary electrophoresis laser-induced fluorescence detection for the determination of a few beta-galactosidase molecules.
abstract: beta-Galactosidase can be assayed by monitoring the generation of the fluorescent products, fluorescein-mono-beta-D-galactopyranoside and fluorescein, when the fluorogenic substrate fluorescein-di-beta-D-galactopyranoside is used. We have used capillary electrophoresis with ultrasensitive laser-induced fluorescence detection to monitor the formation of the fluorescent products of off-column enzymatic reactions. By analyzing as little as 40 pl of the enzymatic mixture we obtain limits of detection of 6.5 x 10(-14) M beta-galactosidase or 1.6 molecules based on the detection of fluorescein-mono-beta-D-galactopyranoside.
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Craig
authors.forename: E A
authors.initials: EA
authors.lastname: Arriaga
authors.forename: P
authors.initials: P
authors.lastname: Banks
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: A
authors.initials: A
authors.lastname: Renborg
authors.forename: M M
authors.initials: MM
authors.lastname: Palcic
authors.forename: N J
authors.initials: NJ
authors.lastname: Dovichi
mesh_terms: D004586:Electrophoresis / Q000295:instrumentation / Q000379:methods*; D005452:Fluoresceins / Q000378:metabolism; D005453:Fluorescence; D007700:Kinetics; D007834:Lasers; D012815:Signal Processing, Computer-Assisted; D001616:beta-Galactosidase / Q000032:analysis*
chemical_list: D005452:Fluoresceins; D001616:beta-Galactosidase