Abstract
A new method for the measurement of complement hemolytic activity of undiluted sera has been developed by using kinetic assay. The complement hemolytic activity was evaluated by the time which required to cause 50% reduction of the initial turbidity, and expressed as CHT 1/2. It seemed that CHT 1/2 reflected the activities of both complement components, mainly early components, and inhibitors and/or inactivators, while CH 50 reflected mainly the activities of late acting components of complement.
Undiluted sera from guinea pigs showed more prolonged CHT 1/2 than that from human beings, in contrast to possesing higher CH 50. Dilution of guinea pigs sera shortened CHT 1/2, suggesting the existence of large amount of inhibitory proteins. This complement kinetic assay using undiluted sera is a completely new concept, and may provide useful information in patients with various diseases clinically.
