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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 XIa

REF 110050

A chromogenic kit for quantitative activity determination of Factor XIa in enriched or highly purified protein preparations. Not intended for analysis of plasma

Measurement Principle

Human FXIa is determined from its activation of human Factor IX and ensuing activation of human Factor X. Generated Factor Xa is then measured with a chromogenic FXa substrate.

The activation of Factor IX is performed in two steps:

1. Initial activation of FIX in the absence of phospholipids.

2. Continued activation of FIX in the presence of FX and phospholipids, therewith allowing concomitant activation of FX.

- A chromogenic kit based upon FXa generation.

- 1 Kit = 2 x 50 test

- Detection Limit = about 0.03 mIU/mL

- No use of human plasma

Features of the Rox Factor XIa kit were presented at the 58th SSC meeting 2012 in Liverpool:



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