Complement Factor P Quantitative ELISA

The Factor P Quantitative Assay is a sandwich ELISA for quantifying human Factor P in serum or EDTA plasma. The assay is based on immobilized antibody in a 96-well plate, which captures Factor P present in samples incubated in the plates. The bound Factor P is detected with a secondary antibody labelled with HRP. The HRP subsequently catalyzes a cleavage of the substrate that induces a color change correlating with the concentration of Factor P in the sample. Factor P (Complement P, Properdin, FP) is a positive regulator and an initiator of the alternative pathway (AP) for complement activation. It binds surface-bound C3 and C5 convertases and stabilizes them to amplify the activation cascade1. Factor P binding increases the half-life of the convertase complex approximately 10-fold2. It is suggested, however debated, that Factor P also can initiate complement activation by binding for example cell surfaces or certain biological substrates, recruiting C3b or C3(H2O) and Factor B and thus initiate the AP pathway1,3. Factor P opposes the negative regulation of Factor H that enhances the dissociation of C3b and Bb and mediates Factor I cleavage of C3b to the inactive iC3b3. Please see instructions for use for more information.