Immunoassay

Abstract

Since the advent of radioimmunoassay in 1959, the immunoassay technology has developed enormously as a very sensitive assay system suitable for wide range of analytes of clinical interest. Current popularity of the noncompetitive principle is attributable to its higher sensitivity, wide dynamic range and shorter incubation time. Recent innovation includes time-resolved fluorescent immunoassay designed to eliminate non-specific fluorescence, amplified enzyme-linked immunoassay and enhanced chemiluminescent immunoassay for ultra-sensitivity, particle counting immunoassay with a high resolution power, simultaneous measurement of multiple analytes, and easy-to-perform multilayer film immunoassays. Despite these advances in the technology, there remain various assay problems such as lack of standardization in reagents, a large interlaboratory variations despite the use of same assay kits, non-linear results in diluted samples and so-called prozone phenomenon.