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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.



2019-06-20 ISTH, Melbourne July 6-10, 2019.

Rossix will present three posters related to analysis of Factor IX at the ISTH in Melbourne:

PB0099 - Evaluation of Lupus Anticoagulant interference in a chromogenic Factor IX kit for determination of

Factor IX activity

PB1294 - Assessment of Factor IX Padua activity with a one-stage clotting method and with FXIa- and tissue factor/FVIIa-based chromogenic methods

PB1295 - Recombinant Factor IX fused with albumin (rFIX-HSA) is underassigned by one-stage methods with silica as contact activator

More information


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