Measurement of alpha-fetoprotein, carcinoembryonic antigen and prostate-specific antigen in serum and heparinised plasma by enzyme immunoassay on the fully automated serono SR1 analyzer.

This paper describes the new enzyme immunoassays for the measurement of alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA) and prostate-specific antigen (PSA) in serum and heparinised plasma as developed for the fully automated Serono SR1 analyzer. Each assay incorporates two monoclonal antibodies in an immunoenzymetric sandwich format using alkaline phosphatase as the label and magnetic solid phase separation. All processing steps are performed by the SR1. The assays have good analytical performance with respect to detection limits (typically 0.24 microgram/l, 1.0 microgram/l and 0.1 microgram/l respectively for AFP, CEA and PSA), precision (within and between run CVs less than 7 and 12% respectively) and recovery of added analyte (100 +/- 10%). Regression analysis of linearity on dilution gives correlation coefficients (r) of 0.9984-1.0000. Tumour marker concentrations measured with these assays are in good agreement with concentrations determined by established immunoassays (r > 0.96). Values measured in samples of healthy probands and samples of patients with malignant and non-malignant diseases are as would be expected for clinically valid assays. The study demonstrates that the measurement of AFP, CEA and PSA in serum and heparinised plasma on the fully automated SR1 analyzer is suitable for the clinical diagnosis, monitoring and management of certain cancers and, in the case of AFP, for prenatal screening of maternal serum.