Native factor I from human serum. Glycoprotein composed of two non-identical disulfide-bonded subunits of M.W. of 50 kDa (α) and 38 kDa (β). Present in normal human serum at about 34 µg/ml. A serine protease that requires protein cofactor in order to effect substrate cleavage. Thus, either Factor H or Factor I mediates cleavage of C3b. C4-binding protein or complement receptor CR1 can function as the cofactor required for Factor I-mediated cleavage of C4b.

Please refer to vial label for lot-specific concentration.

In PBS, pH 7.2.

Following initial thaw, aliquot and freeze (-70°C).

Prepared from serum that has been shown by certified tests to be negative for HBsAg and for antibodies to HIV and HCV.

Solol-Celigny, P., et al. 1982. Clin. Exp. Immunol. 47, 197.
Pangburn, M.K., et al. 1977. J. Exp. Med. 146, 257.

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany

RESEARCH USE ONLY. This product is regulated in France when intended to be used for scientific purposes, including for import and export activities (Article L 1211-1 paragraph 2 of the Public Health Code). The purchaser (i.e. enduser) is required to obtain an import authorization from the France Ministry of Research referred in the Article L1245-5-1 II. of Public Health Code. By ordering this product, you are confirming that you have obtained the proper import authorization.

Toxicity: Standard Handling (A)