Figure 2.

Effect of biotin interference with measured analyte concentrations. Increasing concentrations (0, 10, 20, 30, 40, 50, 100, and 500 ng/mL) of exogenous biotin (Sigma Aldrich, St. Louis, MO) were added into aliquots of residual patient serum matrix. Samples were tested for total testosterone and TSH using competitive immunoassay and immunometric “sandwich” immunoassay methodologies, respectively (Ortho Clinical Diagnostics, Raritan, NJ;Vitros5600). Plots show measured (A) total testosterone and (B) TSH vs biotin concentration.