Automated and manual quantitative assays of choriogonadotropin in serum compared

We found the analytical performance of a rapid, automated assay of human choriogonadotropin (hCG) in serum, the Stratus hCG Fluorometric Enzyme Immunoassay, superior to a widely used manual assay for hCG (Hybritech Tandem-E hCG). The two assays were comparable in sensitivity; recovery; cross reactivity with lutropin, follitropin, and thyrotropin; and freedom from interference from hemoglobin and bilirubin. Patient-correlation studies indicated good quantitative agreement [Stratus hCG = (1.08 X Tandem hCG) - 4.3 int. units/L]. However, intra- and interassay precision was substantially better with the Stratus hCG assay, and this may allow earlier confirmation of pregnancy.