A minimal medium for the growth ofPlasmodium knowlesiin dilution cultures

Abstract

A dilution medium for the cultivationin vitroof the erythrocytic stages ofP. knowlesihas been simplified to contain the following: a balanced salt solution, glucose, isoleucine, methionine, adenosine,p-aminobenzoic acid, biotin and calcium pantothenate. The medium, in the presence of plasma gave better results than the Harvard medium for the growth ofP. knowlesiduring one asexual cycle and also allowed the subculture of the parasites through three asexual cycles before a reduction in the number of parasites was observed.We should like to thank Dr F. Hawking and Dr K. N. Brown for their advice and Mr T. J. Scott-Finnigan for technical assistance. One of us (P.I.T.) received financial assistance from the World Health Organization.