Complement Factor P Functional ELISA

The Factor P Functional ELISA is an enzyme-linked immunosorbent assay (ELISA) that combines principles of the functional complement activity assays with the use of labelled antibodies specific for deposited complement proteins. The amount of deposited complement proteins is proportional to the functional activity 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.