Abstract
Modifications have been made to the fetal mouse liver cell bioassay for erythropoietin in an attempt to make the method easier and to improve specificity. Pooled human serum is used as a diluent for test serum samples, standard and control preparations in order to minimize the influence of other serum constituents on the assay results. Erythroblast proliferation is measured by incorporation of I125 deoxyuridine into DNA. The cell cultures are grown in microtitration plates and harvested semi-automatically on to glass fibre filter mats for determination of radioactivity.