For Research Use Only. Not for use in diagnostic procedures.

A centrally important reaction that occurs during alternative pathway activation is the conversion of the Factor B zymogen to an active proteolytic enzyme. This is accomplished in a two-step reaction. During the first reaction step the Factor B forms a magnesium-dependent complex with C3(H20) or C3b. The C3(H20),B complex is formed only in fluid-phase while the C3b,B complex can be formed either in fluid-phase or on a target surface.  Factor B, which is present in the C3(H20),B or the C3b,B complex, is cleaved into the Ba (33 Kd) and Bb (60 Kd) fragments in the second reaction step by the alternative pathway enzyme, Factor D.

All Quidel complement components are tested for functional activity in a standard lytic or applicable functional assay and for biochemical purity by SDS-polyacrylamide gel electrophoresis. Please refer to the Certificate of Analysis for lot specific information on functional titer.

Quidel's purified human complement components are useful in a wide variety of immunochemical and research applications.