BIOPHEN™ Anti-IIa (220005) is a two stages chromogenic method for the Heparin anti-IIa activity measurement on plasma or purified medium, according to Pharmacopeia (USP, EP). Manufactured by HYPHEN BioMed.
The BIOPHENTM ANTI-IIa (2 Stages Heparin Assay) method is a two stage method based on the inhibition of a constant amount of Thrombin (IIa), by the tested heparin in presence of exogenous antithrombin (stage 1), then hydrolysis of a Thrombin specific chromogenic substrate (CS-01(38)), by the residual Thrombin in excess (stage 2), pNA is then released from the substrate. The amount of pNA released (measured at 405 nm) is then a relation of the residual Thrombin activity. There is an inverse relationship between the concentration of heparin and color development. Heparin + AT [AT Hep.] [AT Hep.] + [IIa (excess)] [FIIa-AT-Hep.] + [residual FIIa] [FIIa (residual)] + Substrate Peptide + pNA