Charles L. Dodson

Mass-Sensing Multianalyte Micro-Array Based Immunoassay by Direct Nir Fluorescence and Quantitative Image Analysis

It has been found that 200 micron-diameter spots of covalently immobilized analyte-specific capture reagent can significantly deplete analyte from several hundred microliters of liquid sample. The quantitative ligand binding assays which result sense the total analyte mass in a sample, rather than concentration, and provide high signal to background by concentrating analytes at the solid-liquid interface. Data from an avidin-biotin model shows the detection of 106 analyte molecules per spot. Preliminary results from a simultaneous multianalyte assay of the four human IgG subclasses validate the avidin-biotin results, and indicate sensitivity comparable to conventional ELISA methods requiring 100 times the antibody mass.