Prospects for the development of a radioimmunoassay technique: Comparative study of two agents for coupling thyroid hormones to bovine serum albumin

The immunogens of thyroid hormones (T3, T4) were prepared by coupling with bovine serum albumin (BSA), using glutaraldehyde and parabenzoquinone as conjugating agents. Optimal parameters for the experimental conditions were defined (incubation time, coupling agent concentrations, etc.). UV-visible spectrophotometry indicates that the thyroid hormones were fixed covalently on the BSA. The coupling ratios evaluated for T3/BSA and T4/BSA were respectively 103 and 54 with parabenzoquinone, and 23 and 8 with glutaraldehyde. The electrophoretic motility in a single band demonstrates the homogeneity of the conjugates. This study has helped select the best conjugate for the development of thyroid hormone immunogens in order to produce antibodies of good quality. (author). 13 refs, 2 figs