[Prospects for use of hapten-heterologous conjugates in immunoassay of thyroid hormones].

The effect of hapten heterology on the characteristics of indirect ELISA methods for determination of thyroxine and triiodothyronine using monoclonal antibodies was studied. The use of the heterologous triiodothyronine-bovine serum albumin conjugate in immunoassays for thyroxine improved the sensitivity of these assays twofold and reduced the cross-reactivity with triiodothyronine from 1 to 0.5% as compared to the homologous variant. By contrast, the heterology in the immunoassays for triiodothyronine appeared inadequate. It was shown that the specificity and sensitivity of hapten immunoassays can be modulated by altering the chemical structure of the hapten-label conjugate, which is most evident in experiments with monoclonal antibodies.