Laboratory Analysis of Study Samples

The plasma Epo level in study samples was determined using a radioimmunoassay ²⁵. In addition, the Epo concentration in the dosing vial was measured using the same radioimmunoassay before it was administered to the subjects. The sensitivity of the assay, defined by the lower limit of quantification, was 1.15 mU/mL. The interassay coefficient of variation was 5.6% to 6.4% and the intra-assay coefficient of variation was 1.4% to 3.5% for three human plasma pools that span the useful range of the assay (i.e., 10.6, 25.8, and 51.7 mU/mL).