Detection of illegal growth promoters in biological samples using receptor binding assays

Abstract In the European Union (EU), the use of growth-promoting substances in meat production is banned. The control of growth promoters, especially steroid hormones, is presently based on expensive and time-consuming chromatographic methods of analysis or, sometimes, for screening purposes, on radio- or enzyme-immunoassays, all of which are often too specific to allow effective multi-analyte control. In order to develop rapid and inexpensive multi-analyte detection tests, we proposed the use of hormonal receptors as detection tools. The system described here (radio-receptor assays) is based on a direct binding assay of steroid hormones to their respective receptors. Human receptors to estrogens (hERα), androgens (hAR), progestagens (hPR) and glucocorticoids (hGR) have been produced by genetic engineering in bacteria or in eucaryotic cells. Binding analyses revealed that the obtained receptor proteins retained a high affinity for their corresponding native ligand. In addition, competition studies confirmed that each of the four receptors displays a specificity profile for a series of analogs in agreement with the literature. Finally, the stability of these recombinant receptors is sufficient to allow their use in test kits.