The Assay of Anti-Haemophilic Globulin

Abstract

Abstract The Biggs, Eveling and Richards assay of anti-haemophilic globulin is examined and some modifications discussed. The statistical design and analysis is offered in a simple form suitable for routine application. The relationships of some defects in the assay to the property of the phospholipid are discussed. It is shown that the method is satisfactory if certain precautions are taken, and if the interpretation is carried out objectively by mathematical methods. Serious errors can arise from neglect of these precautions. Modified assays are described, one of which could probably be used in cases of serious difficulty with reagents. The other apparently depended on the properties of a particular batch of prothrombin. The method was abandoned and is reported here because it is the only modification that gave promise of being more accurate than the original. It is emphasised that the assay is based on hypotheses that have been satisfactorily verified, but that are well recognised to be incomplete. The course of the reaction is by no means clear, and it is unlikely that the assay can accurately be used to compare materials widely dissimilar in qualitative properties.