ISSN:
1619-7089
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Two progesterone-tyraminyl (125I) derivatives were prepared from progesterone-11-hemisuccinate and progesterone-3-0(carboxymethyl)oxime, respectively. The analytical performances of these tracers in the progesterone-anti progesterone-11-hemisuccinyl-BSA system were compared with those of tritiated radioligand assumed as a reference. For all of the 11 antisera tested much higher affinity and titers were observed in the case of ‘homologous’ 125I tracer, which however was found to involve drastic sensitivity losses. On the contrary, quite acceptable dose-response curves and affinity and titers close to those related to tritiated progesterone resulted with the heterologous tracer. These results, interpreted in terms of native ligand-tracer competitivity for the antibody sites, led to the choice of the C3-tyraminyl derivative for the development of a radioimmunoassay method to be compared with the reference tritiated progesterone systems. The two procedures, including minor differences in incubation conditions and B/F separation, were validated for the direct assay of unpurified dried serum extracts. In both cases, satifactory levels of sensitivity, precision and accuracy were proved, the estimates obtained being in a good agreement with data from the literature. On the basis of the present results, some general consideration on the optimization of steroid radioimmunoassay with radioiodinated tracers are tentatively drawn.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00304889
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