Solid-phase enzymoimmunoassay of estrone in serum

This rapid solid-phase enzymoimmunoassay for estrone in serum or plasma is done on microtiter plates after the serum is extracted with dietyl ether. No chromatographic or centrifugation steps are involved. The detection limit of the assay is 380 fg per well (28 pmol/L). Intra- and interassay coefficients of variation for the assay of low, medium, and high concentrations of estrone in plasma were respectively 4.4, 9.3; 2.3, 9.1; and 2.0, 6.3 percent. There was a good correlation (correlation coefficient 0.95) between estrone concentrations measured with this assay and with a commercial radioimmunoassay. The analytical procedure is simple, and one person can assay 80 serum samples per working day. We conclude that the assay is very suitable for serum estrone measurements and is more convenient than published radioimmunoassays.