Levels of plasma 6-keto-prostaglandin F1 alpha (6-keto-PGF 1 alpha) measured in normal subjects by radioimmunoassay show wide variation. In an attempt to develop a sensitive, specific and reproducible assay for the measurement of the circulating metabolites of prostacyclin (PGI2) we examined the different variables involved in radioimmunoassay such as choice of buffer; incubation time and temperature; amount of radioisotope tracer added and the separation method. The method described gives good reproducibility and shows good correlation with in vivo and in vitro doses of PGI2.
McLaren, M., Belch, J. J. F., Forbes, C. D., & Prentice, C. R. M. (1985). Development of a radioimmunoassay for the measurement of prostacyclin metabolites in unextracted plasma. Thrombosis Research, 37(1), 177-183. https://doi.org/10.1016/0049-3848(85)90044-1