The development of a novel immunoassay amplification system and its use in viral detection

A novel amplification system has been developed for the detection of free or antibody-conjugated alkaline phosphatase. The amplification system provides a 100 fold enhancement in the detection of the enzyme, compared to direct detection with chromogenic substrates. The key to the amplification system is the dephosphorylation of a potent phosphorylated inhibitor, and the visualization of this inhibitor using a second, indicator, reaction. This system is shown to provide increased sensitivity for immunoassays detecting either herpes simplex virus or respiratory syncytial virus in clinical samples. In addition, this general concept for amplification may be applicable to a variety of other hydrolytic enzymes, and is demonstrated for the enhanced detection of beta-galactosidase.