A rapid receptor-ligand assay determination of estrogens using surface plasmon resonance

A rapid and simple assay has been developed for the determination of estrog en and estrogen like compounds using surface plasmon resonance (SPR) that m ight be of use in epidemiological studies and potentially may aid the diagn osis of male infertility. The interaction between hER and an immobilised es tradiol-BSA conjugate can be suppressed if the receptor is pre-incubated wi th estradiol or with the estrogen mimic, diethylstilbesterol (DES). The bin ding response of hER to immobilised estradiol-BSA was 184 +/- 40 (n = 3) re sonance units (RU). When preincubated with either free estradiol or DES, th e response was reduced to 93 +/- 8 and 103 +/- 19 RU, respectively (P less than or equal to 0.018). There was no significant difference in the extent to which the level of binding was reduced when these two compounds were com pared (P = 0.47). When receptor was pre-incubated with estradiol to establi sh if binding of the receptor to a zearlenone-BSA (Z-BSA) conjugate also de creased, there was a substantial decrease in binding to Z-BSA, the differen ce in response being significant (P = 0.034). The increased speed with whic h data may be obtained using SPR compared with traditional biological assay s permits greater sample throughput and provides a more quantitative approa ch to defining levels of estrogen and estrogen like compounds in body fluid s. (C) 2001 Elsevier Science B.V. All rights reserved.