Department of Tropical Medicine and Medical Parasitology, Louisiana State University Medical Center, Laboratory Research Branch, National Hansen's Disease Center, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, New Orleans, Louisiana 70112
An immunoperoxidase technique was used to detect hypnozoites and liver schizonts of the primate malaria species Plasmodium vivax and P. cynomolgi bastianellii in Carnoy's-fixed sections. Anti-P. cynomolgi serum and a peroxidase-conjugated anti-monkey IgG serum rendered 7-day pre-erythrocytic forms clearly visible. The technique retains the specificity of the immunofluorescence method while having the advantage of a permanent preparation. Detection of hyponozoites by this alternative method provides further evidence for their plasmodial nature.