Thromb Haemost 1990; 64(02): 267-269
DOI: 10.1055/s-0038-1647298
Original Article
Schattauer GmbH Stuttgart

A Collaborative Study to Establish the Second International Standard for Streptokinase

A B Heath
The National Institute for Biological Standards and Control, South Mimms, Herts, UK
,
P J Gaffney
The National Institute for Biological Standards and Control, South Mimms, Herts, UK
› Author Affiliations
Further Information

Publication History

Received 20 February 1990

Accepted after revision01 May 1990

Publication Date:
25 July 2018 (online)

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Summary

An International Standard for Streptokinase - Streptodomase (62/7) has been used to calibrate high purity clinical batches of SK since 1965. An international collaborative study, involving six laboratories, was undertaken to replace this standard with a high purity standard for SK. Two candidate preparations (88/826 and 88/824) were compared by a clot lysis assay with the current standard (62/7). Potencies of 671 i.u. and 461 i.u. were established for preparations A (88/826) and B (88/824), respectively.

Either preparation appeared suitable to serve as a standard for SK. However, each ampoule of preparation A (88/826) contains a more appropriate amount of SK activity for potency testing, and is therefore preferred. Accelerated degradation tests indicate that preparation A (88/826) is very stable.

The high purity streptokinase preparation, coded 88/826, has been established by the World Health Organisation as the 2nd International Standard for Streptokinase, with an assigned potency of 700 i.u. per ampoule.