Standardization of prekallikrein activator (PKA): the 1st British reference preparation for PKA

A collaborative study on prekallikrein activator (PKA) has been carried out involving four laboratories for the purpose of establishing a British reference preparation for PKA. Samples of two plasma protein fractions (PPF) were assayed against participants' own supplies of the Bureau of Biologics Reference Preparation No. 2 (BoB 2). There was good agreement on the relative PKA activities of the two preparations. One of the preparations, coded 79/572, was established as the 1st British Reference Preparation for Prekallikrein Activator, with an assigned potency of 78.9 units/ml.