BIOPHEN H-CoII kit is a chromogenic assay for measuring Heparin Cofactor II activity in human plasma or in purified systems, using a chromogenic method, manual or automated, based on the inhibition of a constant but in excess amount of thrombin.


Heparin Cofactor II is an anticoagulant protein which inhibits specifically thrombin. This inhibition is highly enhanced by glycoaminoglycans such as Dermatan Sulfate (1). By contrast with Heparin, Dermatan Sulfate activates specifically Heparin Cofactor II (7).

The BIOPHEN H-CoII assay is a chromogenic method based on the inhibition of a constant and in excess amount of thrombin, by the tested Heparin Cofactor II in presence of dermatan sulfate, and measurement of residual thrombin by its amidolytic activity on a thrombin specific chromogenic substrate (SIIa-01). pNA is then released from the substrate.

The amount of pNA released is directly related to the residual thrombin activity. There is an inverse relationship between the concentration of Heparin Cofactor II present in the tested sample and color development, measured at 405 nm Derm. + H-CoII → [Derm. H-CoII][Derm. H-CoII] + FIIa →[FIIa-Derm.-H-CoII] + [FIIa residual][FIIa residual] + S-IIa substrate → Peptide + pNA