Luminescent immunoassay (LIA) methods for steroid hormones.

The application of luminescence to the development of non-isotopic immunoassay methods for steroids and urinary steroid metabolites is reviewed. On-line computer analysis of the light emission is particularly useful, as it reveals the interfering effects of biological compounds on the reaction and this can improve the quality of luminescence immunoassay (LIA) methods. The main characteristics of chemiluminescent tracers are stability, safety, speed and sensitivity of detection, and reliability. Homogeneous methods, not requiring phase separation, have also been reported and validated. Heterogeneous methods which use dextran-coated charcoal or solid-phase techniques can be used for direct determination of urinary steroids in unextracted samples.