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Chromogenic Kits

Learn more about our Chromogenic Kits.

Phospholipid Emulsions

Our highly stable phospholipid emulsions are suitable for use in analyses related to procoagulant and anticoagulant pathways.


Rox Factor IX                                                               CE 

REF 900020

In Vitro Diagnostic Use (Europe)

In Vitro Research Use Only (Outside Europe)

For determination of Factor IX activity in plasma and Factor IX preparations, including potency assignment of FIX concentrates.

- A chromogenic kit based upon FXa generation.

- 1 Kit = 2 x 50 test

- No use of FIX deficiency plasma

- Detection Limit: 0.1% FIX (CLSI EP17-A)

- Quantification Limit: 0.5% FIX (CLSI EP17-A)

- Linearity: 0.5 - 200% (CLSI EP06-A)

Measurement Principle

FIX is activated by human FXIa with concomitant activation of  human FX by generated FIXa in the presence of FVIII, calcium ions and phospholipids. The amount of formed FXa is related to the FIX activity and is measured through hydrolysis of a chromogenic FXa substrate. There is no use of FIX deficiency plasma. The Kit contains a fibrin polymerization inhibitor and a heparin antagonist.



2018-06-29 Posters at the SSC meeting in Dublin July 18-21, 2018.

Steffen Rosén and Rossix AB will present two posters at the SSC meeting in Dublin:

PB229 - Overestimation of recombinant wild type FIX potency by a one-stage method indicated from comparison with a chromogenic FXIa and TF/FVIIa based methods and through discrepant activation of rwtFIX and plasma derived FIX by plasma kallikrein.

PB238 - Underassignment of FIX potency of rFIX-Albumin fusion protein by one-stage methods demonstrated in studies on FXIa and FIXa generation. 


2016-06-22 Publication in collaboration with NovoNordisk

Rosén P, Rosén S, Ezban M, Persson E.

Overestimation of N-glycoPEGylated factor IX activity in one-stage factor IX clotting assay owing to silica-mediated premature conversion to activated factor IX.

J Thromb Haemost 2016; 14: 1420-7.


2015-04-13 Publication in collaboration with AstraZeneca

Ann Lövgren et al. Blood Coagulation and Fibrinolysis, Characterization of thrombin derived from 

human recombinant prothrombin.

Open access: click here