Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Institute of Pathology, Case Western Reserve University, Bethesda, Maryland 20014
It has been observed that a surface coat, 20 nm in thickness, extends from the plasma membrane of extracellular merozoites and that this coat contains strain-specific antigens. In the present study we determined the possible effect of protein in the culture medium on this structure. The surface coat on merozoites in culture medium devoid of protein was indistinguishable by transmission electron microscopy from the coat in a protein-containing medium. This supports the hypothesis that the surface coat originates from the parasite rather than from adsorbed serum protein.
Masamichi Aikawa is supported in part by Research Grant AI-10645 from the United States Public Health Service and by the United States Army Research and Development Command Contract (DADA-17-70-C-0006) (Contribution number 1405).