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

Purified human complement component Factor I. Factor I is a fluid phase complement regulatory enzyme. It consists of two peptide chains with molecular weights of 50 kD and 38 kD, respectively. Factor I is present in plasma at 35 mg/L. With Factor H, CR1 or C4 Binding Protein acting as a co factor, Factor I cleaves the C3b subunit of the alternative and classical pathway convertases, thereby inactivating them.

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.