Analytical Evaluation of the Testosterone Assay on the Bayer Immuno 1™ System

Objectives: To evaluate the analytical performance of the testosterone assay performed on the Bayer Immuno 1™ system from Bayer Corporation. Design and Methods: The precision was measured using three Bayer TESTpoint™ Ligand controls, three Medical Decision Pools and the Bayer SETpoint™ Testosterone calibrators. The linearity was verified by diluting two serum samples containing high testosterone concentrations with the zero calibrator and the minimum detectable concentration determined by repetitive analysis of the zero calibrator. The assay was correlated with the Diagnostic Products Corporation (DPC) Total Testosterone assay using 342 serum samples. The reference values were determined using serum samples from 75 women and 60 men. Results: The assay showed within-run coefficients of variation (CVs) varying from 1.1–8.4% and between-day CVs from 1.5–4.9% for testosterone concentrations varying from 1.77 to 66.96 nmol/L. The minimum detectable concentration was estimated at 0.11 nmol/L. The assay linearity proved excellent. A good correlation between the Bayer Immuno 1 and the DPC assays was observed with different categories of serum samples (Immuno 1 = 1.11 × DPC − 0.32, r = 0.989, Syx = 2.07 nmol/L). The reference values were estimated at 0.3–3.2 nmol/L for females and 9.3–35.6 nmol/L for males. Conclusions: The Bayer Immuno 1 Testosterone assay demonstrates the analytical characteristics required for its utilization in the clinical laboratory.