Comparison of the anticoagulant response of a novel fluorogenic anti-FXa assay with two commercial anti-FXa chromogenic assays

Harris, L., O'Brien, A., Castro-López, V., O'Donnell, J. and Killard, A. (2011) Comparison of the anticoagulant response of a novel fluorogenic anti-FXa assay with two commercial anti-FXa chromogenic assays. Thrombosis Research, 128 (6). pp. 166-170. ISSN 0049-3848 Available from:

[img] Microsoft Word - Accepted Version
PDF - Accepted Version

Publisher's URL:


Introduction Fast and accurate monitoring is crucial in the successful regulation of coagulation therapy. For the treatment of venous thromboembolism, both unfractionated heparin (UFH) and low molecular weight heparins (LMWHs) are commonly administered. The chromogenic anti-factor Xa (FXa) assay is currently considered the ‘gold standard’ assay for monitoring LMWH. However different commercial chromogenic methods often differ when tested with the same samples. Fluorogenic anti-FXa assays have the potential to offer greater benefits over chromogenic assays in terms of greater specificity, sensitivity and they are not so influenced by sample opacity or turbidity. Materials and methods Commercial plasmas were spiked with pharmacologically relevant concentrations (0–1 U/ml) of UFH, enoxaparin, and tinzaparin. The fluorogenic assay was carried out using previously optimized concentrations of 12 nM FXa and 2.7 μM fluorogenic substrate, in addition to 6 μl of 100 mM CaCl2 and 44 μl of plasma. The Biophen® and Coamatic chromogenic assays were carried out according to the manufacturer's instructions. Reaction rates and endpoint values were analyzed and statistical analysis by means of one-way analysis of variance (ANOVA) was performed. Results The fluorogenic anti-FXa assay was found to have the broadest therapeutic range of 0–1 U/ml with CVs of < 5% for UFH and tinzaparin and CVs < 9% for enoxaparin. Despite their limited measuring range, good assay reproducibility was observed with both chromogenic kits. Conclusions This study indicated that the fluorogenic assay is the most sensitive assay with the broadest dynamic range for monitoring LMWH therapy when compared with standard chromogenic assays.

Item Type:Article
Uncontrolled Keywords:Factor Xa, fluorogenic, chromogenic, low molecular weight heparin
ID Code:15651
Deposited By: Professor T. Killard
Deposited On:13 Sep 2011 11:29
Last Modified:16 Nov 2016 18:51

Request a change to this item

Total Document Downloads in Past 12 Months

Document Downloads

Total Document Downloads

More statistics for this item...