Rox Factor IXa

For quantitative determination of human Factor IXa (FIXa) activity as contamination in human Factor IX (FIX) containing concentrates. FIX is a single chain, vitamin K dependent glycoprotein of about 55 KDa, which is activated by FXIa or tissue factor / FVIIa. Activated FIX (FIXa) converts FX to FXa in the presence of FVIII, phospholipids and calcium ions.

Key characteristics

• Excellent tool for determining the degree of preactivation in Factor IX preparations.
• Superior to the NAPTT method for detecting FIXa in recombinant Factor IX preparations*.
• Stability of Reagents after reconstitution 48 hours at 2-8℃.
• Limit of quantification about 0.02 mIU/mL Factor IXa.
• Not intended for analysis of plasma samples.

* Böhm E, Dockal M, Pilz J, Schrenk G, Varadi K, Scheillinger F. Superiority of the chromogenic assay specific for activated factor IX (FIXa) over the non-activated partial thromboplastin time (NAPTT) clotting assay in detecting FIXa in recombinant FIX (rFIX) preparations. XXIV ISTH Congress 2013; Poster PB1.39-6.

Measurement principle

FIXa activity in FIX containing samples is determined in a chromogenic method, in which human FX is activated by contaminating human FIXa in the FIX sample in the presence of FVIII, thrombin, calcium ions and phospholipid. The amount of FXa formed is related to the FIXa activity and is determined from the hydrolysis of a chromogenic FXa substrate. The FIXa activity of the sample is assigned vs. a FIXa standard with FIXa activity expressed in International Units (IU).

Kit information

• 1 Kit = 2 x 50 tests (manual microplate method).
• Limit of quantification = About 0.02 mIU/mL FIXa.
• For In Vitro Research Use only.
• Not intended for analysis of plasma samples.
• FIXa calibrator and control not included – available as separate products.