Technochrom® anti-Xa is a system of reagents for the chromogenic determination of direct and indirect Xa inhibitors in human citrated plasma. The assay is based on the inhibition of activated factor X (FXa) by Antithrombin (AT) in the presence of heparin as measured by a chromogenic FXa substrate.

technochrom anti-xa chromogenic assay test kit

  • Reagent 1 (R1): 1 x 20 ml, anti-Xa buffer, TRIS-EDTA buffer; pH 8.4; contains sodium azide (<1g/l) as a preservative
  • Reagent 2 (R2): 1 x 4 ml, Bovine Factor Xa, lyophilized; 1 vial; about 24 nkat
  • Reagent 3 (R3): 1 x 4 ml, Chromogenic substrate, lyophilized; 1 vial; 4.8 mg

MATERIAL REQUIRED (not provided with the kit)

  • Distilled water
  • Acetic acid (20%) or 2% citric acid (end point method)
  • Plasma Calibrators with a known concentration of:
    • Fondaparinux (Technoview® Arixtra® Calibrator Set) (catalog # 5090010)
    • Technoview® LMW Heparin Calibrator Set (catalog # 5090040)
    • Technoview® UF Heparin Calibrator Set (catalog # 5090070)
    • Technoview® Rivaroxaban Calibrator Set (catalog # 5090170)
    • Technoview® Apixaban Calibrator Set (catalog # 5090269)
  • Control plasmas for:
  • Common clinical laboratory equipment (spectrophotometer set at 405nm, water-bath set at 37°C, stop-watch, test tubes, pipettes,…)
[Xa-Inhibitor] + Xa (excess) [Xa-Inhibitor – Xa] + Xa (residual)
Xa (residual) + substrate pNA

The amount of pNA, released by enzymatic hydrolysis, is measured at 405 nm. There is an inverse relationship between the amount of heparin present in the sample and color development.

Calibration Curve

  • For Fondaparinux (Arixtra®) research, a calibration curve is constructed using Technoview Arixtra® CAL (catalog # 5090010)
  • For LMW Heparin research, a calibration curve is constructed using Technoview® LMW CAL (catalog # 5090040)
  • For UFH research, a calibration curve is constructed using Technoview® UFH CAL (catalog # 5090070)
  • For Rivaroxaban research, a calibration curve is constructed using Technoview® Rivaroxaban CAL (catalog # 5090170)

Ceveron® alpha

Technoclone provides application sheets for Ceveron® alpha. The application sheets contain analyzer/assay specific handling and performance information which may differ from that provided in this instruction for use. In this case the information contained in the application sheets supersedes the information in this instruction for use. Please consult the instruction manual of the Ceveron® alpha.


Reproducibility was determined with different samples (in series and day to day). The following results were obtained:

Intra assay Intra assay
LMW level 1 (1.37 u/ml) 1.6% 24 LMW level 1 (1.36 u/ml) 1.5% 6
LMW level 2 (0.52 u/ml) 2.5% 24 LMW level 2 (0.37 u/ml) 2.5% 6
UFH level 1 (1.26 u/ml) 0.7% 24 UFH level 1 (1.45 u/ml) 2.6% 6
UFH level 2 (0.42 u/ml) 2.1% 24 UFH level 2 (0.06 u/ml) 5.7% 6