The influence of heterologous combinations of antiserum and enzyme-labeled estrogen on the characteristics of estrogen enzyme-immunoassays

The sensitivity of enzyme-immunoassays for estrogens strongly depends on the particular combination of antiserum and estrogen-enzyme conjugate being used. Homologous assays were relatively insensitive. Using different estrogen derivatives to prepare the immunogen and the estrogen-enzyme conjugate, more sensitive assays could be obtained, with little adverse effect on the specificity. The estrogen derivatives differed in type of estrogen, nature and position of the side chain. The general implications of these findings for hapten immunoassay are discussed.