Chromogenix Coamatic® Antithrombin is a chromogenic assay kit for in vitro diagnostic determination of antithrombin activity in human plasma. The use of factor Xa in preference to thrombin eliminates interference from heparin cofactor II and thrombin inhibitors. This FXa-based antithrombin test kit has been shown to discriminate better between AT-deficient and non-AT-deficient individuals than a thrombin-based assay [Demers et al 1993]. It also gives accurate results in patients who are receiving heparin therapy [Bohner et al 1994]. Simple, accurate and convenient. All methods are based on FXa inhibition. Allows accurate determination of antithrombin in patients receiving heparin therapy. Superior reagent stability. Validated and documented protocols for a wide range of instruments. Suitable for both large and small laboratories.

  • Use of FXa instead of thrombin eliminates interference from heparin cofactor II anddirect thrombin inhibitors
  • Highly sensitive FXa chromogenic substrate and superior reagent stability
  • High accuracy and precision – CV values less than 5%
  • Applications available for a wide range of automated coagulation analyzers, including the BCS
  • Accurate determinations in patients receiving heparin therapy
  • Suitable for both large and small laboratories

Reagents, Packaging, Storage, Stability

  1. Substrate S-2765™, 1 vial, 6 months, 2-8°C
  2. Buffer with Heparin, 1 vial, 3 months, 2-8°C
  3. FXa, 1 vial, 3 months, 2-8°C

Determinations per kit:

  • 50 (test tube)
  • 200 (microplate)
  • up to 130 (automated)
AT + Heparin ———> [AT · Heparin]
[AT · Heparin] + FXa (excess) ———> [AT · Heparin·FXa] + FXa (residual)
FXa (residual)
S-2765™ ———> Peptide + pNA

AT = Antithrombin

Antithrombin is a circulating plasma protein that functions as an important regulator of blood coagulation. It inactivates several enzymes of the coagulation cascade, in particular thrombin and factor Xa. Since a link between hereditary antithrombin deficiency and thrombosis was established in 1965, there has been increasing clinical interest in antithrombin and a need for simple and accurate determination. Assays based on chromogenic peptide substrates are now available, allowing photometric detection of antithrombin activity in plasma. Read more…