Journal Article

Antithrombin III Determination in Nearly-Undiluted Plasma

Thomas W. Stief

in Laboratory Medicine

Published on behalf of American Society for Clinical Pathology

Volume 39, issue 1, pages 46-48
Published in print January 2008 | ISSN: 0007-5027
Published online September 2015 | e-ISSN: 1943-7730 | DOI: http://dx.doi.org/10.1309/AYJPM5QWLV9KMHQV
Antithrombin III Determination in Nearly-Undiluted Plasma

Show Summary Details

Preview

Background

Antithrombin III (AT3) in highly diluted plasma may not react like AT3 in circulating blood.

Methods

To avoid artificial changes of the plasma matrix by strong dilution, a new AT3 test was developed: 25 μL citrated plasma reacts with 5 μL thrombin reagent, 92 IU/mL (15.3 IU/mL final) bovine alpha-thrombin, 10 IU/ml (1.7 IU/mL final) heparin, 1,480 mM (247 mM final) arginine, pH 7.4, 6% human (albumin) for 1 min (37°C). Plasma is only diluted by 20%. Then 100 μL 2.5 M arginine, 0.13% Triton X 100, and 50 μL 1 mM (0.28 mM final) chromogenic thrombin substrate CHG-Ala-Arg-pNA are added and increase in absorbance (ΔA/min) is determined.

Results

Antithrombin III is specifically determined with 1 min reaction time; from the third minute onward a second thrombin inactivator significantly acts.

Conclusion

This undiluted AT3 test uses approximately 10 IU/ml (final acitivity) thrombin, which is the approximate peak activity of thrombin caused by intrinsic hemostasis activation.

Journal Article.  0 words. 

Subjects: Haematology

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.