The development of an enzyme-linked immunosorbent assay for the determination of cortisol binding globulin.


Department of Human and Animal Physiology University of Stellenbosch, South Africa


A simple, reliable and reproducible enzyme-linked immunosorbent assay (ELISA) using polyclonal antibodies for human cortisol binding globulin (CBG) has been developed. The sensitivity of the ELISA (1.20 fmol CBG/well) compared favourably with the sensitivity of other immunoassays. The excellent agreement (r= 0.98) seen between the present study and a binding assay indicates that the polyclonal antibodies used recognize only intact steroid-binding CBG. The intra- and inter-assay coefficient of variation (4.0% and 7.1% respectively) compared favourably with those reported by other authors.