Human FVII Chromogenic Activity Assay KitThe Human Factor VII (FVII) Chromogenic Activity Kit is developed to determine human FVII activity in plasma, serum, and cell culture supernatants. The assay couples immunofunctional and indirect amidolytic assay. An antibody specific for human FVII has been pre-coated onto a microplate, and active FVII is bound to the immobilized antibody. The assay measures the ability of lipoprotein TF/FVIIa to activate factor X (FX) to factor Xa. The amidolytic activity of the TF/FVIIa complex is quantitated by the amount of FXa produced using a highly specific FXa substrate releasing a yellow para-nitroaniline (pNA) chromophore. The change in absorbance of the pNA at 405 nm is directly proportional to the FVII enzymatic activity.