A comparision of methods for the initial concentration of erythropoietin from human urine

Evaluation of some serum erythropoietin concentration procedures using serum-containing and serum-free in vitro bioassays

Studies are reported which were designed to further refine a serum-free culture method to assess the erythropoietic response of fetal mouse liver cells. The objective was to employ such a serum-free system with deproteinized serum concentrates as the test materials in a potentially highly specific assay for erythropoietin (Ep). A serum-free culture method is described which permits responses to Ep (125I-deoxyuridine incorporation) closely comparable to those observed in cultures containing optimal concentrations of sera. Mean recoveries of Ep were acceptable in each of three variations of a serum concentration procedure. However, no correlations were evident between Ep titers in whole sera and those in the concentrates (assayed in both serum-free and serum-containing cultures) with deproteinization and/or concentration procedures involving serum acidification and exposure to boiling water temperature.

Erythropoietin assay using fetal mouse liver cell cultures: a modified technique using semi-automatic harvesting of I125 deoxyuridine labelled erythroblasts

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.