methodological approach to beta-endorphin assay in biological samples

ABSTRACT

In this study, a methodological approach to B-endorphin in biological fluids [seminal plasma, blood plasma and serum] was done. Measurement of beta-endorphin was performed by immunoassay method [immunoradiometric assay [IRMA] and radioimmunoassay [RIA]], either directly or proceeded by extraction procedures, e.g. Sep Pak [C18], affinity columns of sepharose particles and HPLC. A recovery study of B-endorphin was done to assess the binding effect of endogenous proteins in test samples on assay performance. It can be concluded that measurement of B-endorphin in peripheral blood samples [plasma and serum] can be performed by a direct immunoradiometric assay without extraction methods. As regards the measurement of B-endorphin in seminal plasma by IRMA and RIA, it must be proceeded by acidification of the sample, boiling and extraction by Sep Pak [C18] cartridges