MICROCHIP ELECTROPHORETIC IMMUNOASSAY FOR SERUM CORTISOL

An immunoassay performed using a microchip electrophoretic system is d escribed, Separation and quantitation of free and bound labeled antige n in a competitive assay are carried out in channels micromachined int o fused silica substrates. Such microchips are attractive because of t heir small size, ruggedness, and amenability to automated handling. Th e assay achieves the determination of cortisol in blood serum over the range of clinical interest (1-60 mu g/dL) without the need for extrac tion or other sample preparation steps. The separation is performed in less than 30 s. Very high throughput is possible by operating the ass ay in multiple channels in parallel, These characteristics make microc hip electrophoretic systems a promising technology for the rapid analy sis of clinical samples.