Enzyme immunoassay by capillary electrophoresis with laser induced fluorescence detection

Antibody (Ab) labeled with alkaline phosphatase was separated and detected by a capillary electrophoresis system equipped with a laser induced fluores cence detection system. The combination of B/F separation and the LIF detec tion of the label enzyme is potentially useful for a highly sensitive detec tion of antigen (Ag). After B/F separation by capillary electrophoresis (CE ), label enzymes catalyze the hydrolysis of fluorescein diphosphate in the running buffer for several minutes, producing fluorescein. Experiments with various ratios of Ab to Ag revealed that the faster peak was the complex o f Ab and Ag, and the other was free Ab. (C) 1999 Elsevier Science B.V. All rights reserved.