Standardization of prekallikrein activator (PKA): the 1st International Standard for PKA

A international collaborative study was carried out to establish an international standard for prekallikrein activator (PKA). The candidate material, coded 82/530, was assayed against the Office of Biologics (FDA) PKA reference preparation No. 2 (OoB 2) and the 1st British Reference Preparation for PKA. There was good agreement between participant laboratories on the relative PKA activity of the three preparations. Preparation 82/530 has been established by the World Health Organization as the 1st I.S. for PKA, with an assigned potency of 85 International Units per ampoule.