Competitive immunoassay using protein g affinity capillary chromatography with laser induced fluorescence detection

Abstract

A simple approach to perform competitive immunoassay using protein G affinity capillary chromatography and laser induced fluorescence (LIF) detection was described. Bovine serum albumin (BSA) was used as a model to test the performance of the system. The assay used fluorescein isothiocyanate (FITC) labeled BSA as a tracer and an anti-BSA monoclonal antibody as the immunoreagent. Capillaries with inner diameter of 150 μm were packed with recombinant protein G bound perfusive support and used to capture the immunocomplexes, which were subsequently desorbed by 100 mM glycine (pH 9.0) and then detected using LIF. The results demonstrated the feasibility to perform competitive immunoassay using this system with high sensitivity and small sample size.