Download PDF
Thromb Haemost 1995; 74(03): 900-903
DOI: 10.1055/s-0038-1649844
Original Article
Coagulation
Schattauer GmbH Stuttgart

The International and “NIH” Units for Thrombin - How Do They Compare?

Patrick J Gaffney
The National Institute for Biological Standards and Control, South Mimms, Potters Bar, Hertfordshire, UK
,
Tracey A Edgell
The National Institute for Biological Standards and Control, South Mimms, Potters Bar, Hertfordshire, UK
› Author Affiliations
Further Information

Publication History

Received 19 August 1994

Accepted after resubmission 27 April 1995

Publication Date:
09 July 2018 (online)

  PDF Download  Permissions and Reprints

Summary

The current International Standard (IS) for α-thrombin was established in 1991. It was related in unitage with the 1st IS for Thrombin established in 1975 and contains 100 IU of thrombin activity. The National Institute of Health (NIH) standard (Lot J) is in common use for the calibration of commercial thrombin reagents and this study reports on a comparison of the thrombin units defined by these 2 standards. This study has indicated that one “NIH” unit is equivalent to 1.1 to 1.3 IU of thrombin, depending on the influence of PEG in the assay. A unitage ratio figure of 1.15 was recommended following analysis of data obtained in the presence and absence of PEG in the comparative assays. This was confirmed by amidolytic assay data.

 

  • References

  • 1 Robertson I, Gaffney PJ, Bangham DR. Standard For human thrombin. Thromb Diath Haemorrh 1975; 34: 3-19
    PubMedGoogle Scholar
  • 2 Gaffney PJ. Thrombin and thrombin-like standards. Thromb Haemost 1977; 38: 562-566
    Article in Thieme ConnectPubMedGoogle Scholar
  • 3 Gaffney PJ, Heath AB, Fenton JWII. A collaborative study to establish an international standard for alpha-thrombin. Thromb Haemost 1992; 67: 424-427
    Article in Thieme ConnectPubMedGoogle Scholar
  • 4 Fenton II JW, Fasco MJ, Stackrow AB, Aronson DL, Young AM, Finlayson JS. Human thrombins. Production, evaluation and properties of α-thrombins J Biol Chem 1977; 252: 3587-3598
    PubMedGoogle Scholar
  • 5 Campbell PJ. International Biologieals Standards and Reference Preparations. I. Preparation and presentation of materials to serve as standards and reference preparations J Biol Stand 1974; 2: 249-258
    CrossrefPubMedGoogle Scholar
  • 6 Finney DJ. Statistical Methods in Biological Assay. 3rd. Edition Griffin; London: 1978
    Google Scholar
  • 7 Fenton JW, Fasco MJ. Polyethylene glycol 6,000 enhancement of the clotting of fibrinogen solutions in visual and mechanical assays. Thromb Res 1974; 4: 809-817
    CrossrefPubMedGoogle Scholar
  • 8 Ray MJ, Just SJ E, Carroll PA, Hawson GA T. A carryover artefact when using a recombinant thromboplastin on an automated coagulation analyse. Blood Coagulation Fibrinolysis 1994; 5: 315-316
    CrossrefPubMedGoogle Scholar
  • 9 Gaffney PJ, Lord K, Brasher M, Kirkwood TBL. Problems in the assay of thrombin using synthetic peptides as substrates. Thromb Res 1977; 10: 549-556
    CrossrefPubMedGoogle Scholar