title: Equations for the calculation of factor VIII potencies from the results of parallel-line clotting-time assays.
abstract: An equation was derived: 1nC01 = 1nD1 - (a2/a1)1nD2 + (a2/a1) 1nC02 + 1/a1(b1-b2) which related the potency of a sample (C01) to the potency of a standard (C02) via the dilution factors (D1 & D2) that produced common clotting times for the sample and standard. This equation could not be used in practice since C01 and b1 were both unknown. Derivation of a usable formula for calculating sample potencies was found to require the assumption that b1 = b2. It was found that b is not always a constant in Factor VIII assays and may vary with the nature of the clotting assay mixtures.
mesh_terms: D001780:Blood Coagulation Tests; D005169:Factor VIII / Q000494:pharmacology*; D006801:Humans; D012016:Reference Values; D014914:Whole Blood Coagulation Time
chemical_list: D005169:Factor VIII