Native, human C1 complement component. C1 is the first component of the classical complement pathway. It is a calcium dependent complex of C1q, C1r, and C1s subcomponents which are present in the C1 complex at molar ratios of 1:2:2 respectively. Binding of C1 to classical pathway activators results in the conversion of the proenzyme C1s subcomponent to an active C1s enzyme. C1s enzyme cleaves both C4 and C2, resulting in formation of the C3 cleaving enzyme, C4b, C2a, of the classical complement pathway. C1 concentration is based on functional activity measurements relative to a normal serum standard pool.

Please refer to vial label for lot-specific concentration.

Toxicity: Standard Handling (A)

In 300 mM NaCl, 50 mM sodium acetate, 50 mM EACA, 25 µM NPGB, 10 mM benzamidine, 10 mM EDTA, 40% glycerol, pH 5.5.

Cooper, N.R. 1985. Adv. Immunol. 37, 151.
Ziccardi, R.J. and Cooper, N.R. 1977. J. Immunol. 118, 2047.

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