Summary and Conclusions
In bacterial complement fixation the inactivation of complement occurs by virtue of the removal of one or more of the C′ components. The bacterial strains employed in these experiments inactivate human complement by fixation of either C′2 or C′3 principally. It is pointed out that these components are also those present in least titer in human complement. “Over-fixation” results in the progressive removal of the other components.
The complement components which are fixed to sensitized V. comma from specifically inactivated complements (siC′), retain their ability to participate in a subsequent bactericidal reaction. Further, the hemolytic functions of the C′ components remaining in the supernate after such a fixation, closely parallel the bactericidal functions of the fixed C′ components.
Aided by a grant from the Commonwealth Fund.