Zymosan is prepared (Pillemer, L. and Ecker, E.E., (1941)) from actively growing yeast (Saccharomyces cerevisiae). After removal of cellular contents the isolated cell walls remain. This is zymosan and it is primarily composed of the highly cross-linked polysaccharides alpha-D-mannan, beta-D-glucan, and other minor polysaccharide polymers. Fresh zymosan, and especially zymosan stored as a dried powder, must be activated to develop its full complement-activating activity (Minta, J., 1983). This is done by refluxing zymosan in saline at 100oC for two hours. This process has been performed for customers on the zymosan offered by CompTech and it is sold as a pre-activated suspension in saline. The product has been shown to be stable for four years if kept frozen. It is stable at 4oC for several months if not contaminated by microbial growth.
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