A simple way to determine nonspecific effects of plasma and serum components in radioreceptor assays and radioimmunoassays for human chorionic gonadotropin
Rao, C.V.; Hussa, R.O.
American Journal of Obstetrics and Gynecology 142(2): 153-158
1982
ISSN/ISBN: 0002-9378 PMID: 7055179 DOI: 10.1016/s0002-9378(16)32329-8Document Number: 385483
A simple approach is validated for the determination of nonspecific effects of human plasma and serum in the radioreceptor assays and radioimmunoassays for human chorionic gonadotropin (hCG). The approach is based on the findings that, despite differences in the degree of inhibition of 125I-hCG binding to its receptors and antibodies by nonhormonal components in different dilutions of pool plasma and serum, the standard curves (plotted as the percentage of control for each serum or plasma dilution) are superimposable. The approach consists of (1) running a single standard curve with no pool plasma or serum, (2) including a set of "correction" tubes which contain pool plasma or serum diluted correspondingly to the dilution of the unknown samples in the assay, (3) dividing the counts per minute found in the correction tubes into the counts per minute of the unknown samples and multiplying by 100, and (4) using this value to obtain the amount of hCG in the unknown samples by comparison with the no pool plasma or serum standard curve.