AnaSpec has announced the release of the industry first fluorimetric Factor Xa activity assays - The SensoLyte® 520 Factor Xa Assay Kit and the SensoLyte® Rh110 Factor Xa Assay Kit.

The SensoLyte® 520 Factor Xa Assay Kit employs a FRET (5-FAM/QXL™ 520) substrate and the SensoLyte® Rh110 Factor Xa Assay Kit, a substrate labeled with the fluorophore, Rh110.

Both substrates are fluorescent substrates emitting in the green range of 520 nm, with excitation at 490 nm.

The longer-wavelength spectra of 5-FAM and Rhodamine 110 provide greater sensitivity and less interference from other reaction components, making these kits ultra-sensitive.

The detection limit of the SensoLyte® 520 kit can reach as low as 7.8 ng/mL while the SensoLyte® Rho110 reaches as low as 0.31 ng/mL.

Key highlights for AnaSpec’s new SensoLyte® Factor Xa Assay Kits:

• Kits optimized to detect Factor Xa enzyme activity
• Fluorometric, long wavelength (Ex/Em=490/520 nm) read-out assays
• Minimal autofluorescence
• Kits provide ample reagents to perform 100 assays in a 96-well plate format
• Assays can be completed in one hour

Factor Xa (FXa) is a serine endopeptidase composed of two disulfide-linked subunits. FXa leads to blood clot formation by converting prothrombin to thrombin through the prothrombinase complex.

FXa is generated from zymogen Factor X via the intrinsic and extrinsic pathways and is the rate-limiting step in the propagation of thrombin generation.

In the presence of Ca2+ ions, FXa forms prothrombinase with factor Va on the phospholipid membrane of the activated platelets. FXa has emerged as an attractive target for drug discovery for thromboembolic diseases.