An immunoprecipitation assay in the multicommutated flow analysis format
In this contribution, a multicommutated flow analysis (MCFA) system for immunoprecipitation assays is presented. The developed bioanalytical system constructed from microsolenoid devices coupled with an optoelectronic flow-through nephelometric detector is sufficient to monitor the kinetics of antigen–antibody interactions, the effect of which is turbidity. Because of the uncommon shape of the immunoprecipitation response curve, the developed MCFA system contains a special module for on-line dilution of the analyzed samples and for single-standard calibration. As a model analyte and an immunoreceptor for the presented investigations, human albumin and antibody for this albumin were used, respectively. The proposed MCFA system is characterized by robust construction, low reagent consumption (maximum 42 μL of undiluted reagent for the analysis of one sample) and relatively high throughput under optimal conditions (approximately 18 measurements per hour). The analytical usefulness of the developed MCFA system for clinical analysis has been experimentally confirmed. Samples of human urine were analyzed for the needs of microalbuminuria diagnostics and satisfactory analytical results have been obtained.