For In Vitro Diagnostic Use.

BIOPHEN™ AT (Anti-Xa) is a chromogenic assay measuring Antithrombin (AT) activity via the anti-Factor Xa pathway. Principle: patient AT + heparin (R1) ? AT-heparin complex inhibits bovine FXa ? residual FXa measured with chromogenic substrate (R2). AT activity inversely proportional to residual FXa. For thrombophilia screening (AT deficiency is a high-risk inherited thrombophilia with 5-8x increased VTE risk), DIC monitoring, heparin resistance investigation, and liver function assessment. Calibrate with Plasma Calibrator (222101). Controls: Normal (223201) + Abnormal (223301). Also available: AT anti-IIa variant and latex immunoassay for antigen levels. FDA 510(k) cleared. CE-IVD.