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Factor IX Antigen Kit


The VisuLize™ FIX Antigen Kit is intended to quantitatively measure Factor IX (FIX) antigen in human plasma and factor concentrates. The biological importance of FIX is demonstrated in hemophilia B (Christmas disease), an X-linked congenital bleeding disease resulting from a quantitative (low activity and low antigen) or qualitative (low activity and normal antigen) defect in FIX function. The congenital deficiency of FIX may be classified as severe (1% FIX activity), moderate (between 1 and 5% FIX activity) or mild (between 5 and 40% FIX activity). The laboratory diagnosis of FIX deficiency typically involves quantitative determinations of procoagulant levels i.e., functional activity of FIX.¹ An ELISA for FIX antigen may be used in conjunction with functional assays in the area of gene therapy, assessment of FIX concentrates, determination of carrier status as well as distinguishing those patients with cross-reactive material (i.e., low functional activity but near normal antigen levels of FIX).


  • Rapid sandwich ELISA to measure FIX antigen (FIX:Ag)
  • 70 minutes total incubation time
  • FIX:Ag reported as International Units/mL traceable to WHO standard for FIX antigen
  • Detection limit to 0.005 IU/mL FIX:Ag (0.5%)
  • Includes normal and low controls


  • Quantification of FIX antigen in plasma and therapeutic concentrates
  • Diagnosis and characterization of hemophilia B
  • Carrier testing for hemophilia B
  • Thrombophilia screening

¹ White GC, Roendaal, F. Aledort LM, Lusher JM, Rothschild C, Ingersley J. Definitions in Hemophilia, Recommendation of the Scientific Subcomittee on Factor VIII and Factor IX of the Scientific and Standardization Committee of the International Society on Thrombosis and Hemostasis, Thrombosis and Hemostasis, 2001, 85, p. 560.


Storage and Shelf Life


between 2°C and 8°C






Please inquire

Available Formats

Cat # Format

Pre-coated 96-well plate; 6x16 strip format

2 x Calibrator Plasma

2 x Control Plasma A

2 x Control Plasma B

1 x 50.0 mL 20X Wash Buffer Concentrate

3 x 20.0 mL 2X Buffered Sample Diluent

1 x 12.0 mL Detecting Antibody

1 x 12.0 mL TMB Substrate

1 x 12.0 mL Stop Solution

US and Canada. Available For Research Use Only elsewhere (catalog number FIX-AG-RUO).
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