[Thrombin Reference Standard (Control 031) of National Institute of Health Sciences].

The "Thrombin Reference Standard (Control 031", of National Institute of Health Sciences was prepared. The precision of filling into ampoule was about 11.5% as C.V. The content of alpha-thrombin was about 89%. The thrombin potency of the standard material was assayed against the Thrombin Reference Standard (Control 961) according to the method of JP-X IV and the potency was 692 +/- 35 units/ampoule. From the results, the potency of the proposed material for Thrombin Reference Standard was defined as 690 units per ampoule.