Antithrombin

Antithrombin (AT) deficient plasma and antithrombin reference preparations from 5-Diagnostics for chromogenic anti-Xa and anti-IIa assay calibration, pharmacopoeial heparin potency testing, and thrombophilia research. Antithrombin is the primary physiological inhibitor of coagulation serine proteases — particularly thrombin and Factor Xa — and is the essential cofactor for heparin in both clinical anticoagulation and pharmacopoeial heparin potency assays.

AT reference concentrate preparations from 5-Diagnostics are supplied at defined specific activity (IU/mg), traceable to WHO International Standard for Antithrombin, for use as the exogenous AT source in two-stage chromogenic heparin potency assays (USP Chapter 208, Ph. Eur. 2.7.12) where the AT content of the assay system must be controlled precisely.

Antithrombin-depleted plasma is produced by affinity depletion of AT from human citrated plasma using heparin-Sepharose affinity chromatography, with residual AT confirmed below 1% of normal — used in research studying heparin activity in AT-independent mechanisms and for validating AT dependence of anti-Xa assay systems.

Both AT reference concentrate and AT-deficient plasma include lot-specific activity certificates with traceable calibration data. For Research Use Only. Not for use in diagnostic procedures.