title: [Problems of dextran-charcoal-separation of free from antibody-bound steroid in a direct radioimmunoassay of progesterone without chromatography and extraction (author's transl)].
abstract: A method for radioimmunoassay of serum progesterone is described which does not require extraction. A chromatographic step is not necessary because of the high specifity of the antibody. The intrassay coefficient of variation was 6.1% and the interassay coefficient of variation was 8.4%. The detection limit was 10 pg/tube that means 1 ng/ml serum. The test on parallelity was correct up to 10 microliter serum. The results compared with results of a radioimmunoassay with extraction were identical. High concentrations of hormone in serum and an antibody of high specifity are required for the direct radioimmunoassay of steroids. Using the dextran-charcoal system for separation of free from antibody-bound steroid the relationship of the quantity of serum to the quantity of charcoal is of great importance. These problems are discussed.
mesh_terms: D002606:Charcoal; D003911:Dextrans; D011374:Progesterone / Q000032:analysis*; D011485:Protein Binding; D011863:Radioimmunoassay / Q000379:methods
chemical_list: D003911:Dextrans; D002606:Charcoal; D011374:Progesterone
vernacular_title: Problematik der Dextran-Aktivkohletrennung von freiem und gebundenem Steroid im direkten Progesteronradioimmunoassay ohne Chromatographie und Extraktion.