Fluorescence-Based Enzymatic Assay by Capillary Electrophoresis Laser-Induced Fluorescence Detection for the Determination of a Few β-Galactosidase Molecules

✍ Scribed by D. Craig; E.A. Arriaga; P. Banks; Y. Zhang; A. Renborg; M.M. Palcic; N.J. Dovichi

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 543 KB
• Volume: 226
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.1995.1202

✦ Synopsis

(\beta)-Galactosidase can be assayed by monitoring the generation of the fluorescent products, fluoresceinmono- (\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 \mathrm{pl}) of the enzymatic mixture we obtain limits of detection of (6.5 \times 10^{-14} \mathrm{M} \beta)-galactosidase or 1.6 molecules based on the detection of fluoresceinmono- (\boldsymbol{\beta})-D-galactopyranoside. 1995 Academic Press, Inc.