CVF-NHS is generated by activating the complement system in normal human serum with cobra venom factor (CVF) (CompTech #A150) purified from the venom of Naja naja kaouthia. CVF from Naja naja kaouthia produces an enzyme that cleaves both human C3 and C5. The affinity of the Naja naja kaouthia CVF for C5 is so high that it primarily consumes C5 first, then C3 ((Rawal, N. and Pangburn, M.K. (2000)).
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