Summary: This paper describes the new enzyme immunoassays for the measurement of oc-fetoprotein (AFP), carcinoembryonic antigen (CEA) and prostate-specific antigen (PSA) in serum and heparinised plasma as developed for the fully automated Serono SRI™ 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 SRI.The assays have good analytical performance with respect to detection limits (typically 0.24 g/l, 1.0 g/l and 0.1 g/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 SRI 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.

Summary: This paper describes a fully automated assay on the Serono SRI™ for the measurement of cortisol in serum, heparinised plasma and urine. The assay incorporates a specific polyclonal antibody to cortisol and cortisol conjugated to alkaline phosphatase as a label. Following immunoincubation, bound and free labelled cortisol are separated by magnetic sedimentation of the antibody complex. Phenolphthalein is liberated by the enzymatic hydrolysis of the substrate (phenolphthalein monophosphate) and the absorbance generated is measured as the assay end-point. All processing steps are performed by the SRI.The assay has good analytical performance with respect to precision (within and between run CVs less than 10 and 11.5% respectively), detection limit (less than 5 nmol/1) and recovery of added cortisol (100 ± 10%). The assay agrees well with cortisol concentrations determined by ID-MS and by established immunoassays (r > 0.96). Reference ranges of normal urine samples (pretreated by solvent extraction) are in good agreement with accepted values.The study demonstrates that the SRI Cortisol assay on the SRI analyzer is suitable for the routine determination of cortisol in serum, heparinised plasma and urine samples. Introduction^, . x , , ·ι_.ι_ r r* r 11