Effect of ethidium bromide on growth and morphology of Leishmania tarentolae promastigotes in vitro.

Incubation of Leishmania tarentolae promastigotes in 0.01 microgram/ml ethidium bromide in Neo Ye medium for 96 h resulted in 60% inhibition of cell growth and 91% dyskinetoplasty. After 48 h incubation in ethidium bromide over 50% of the cells were scored dyskinetoplastic by light microscopy although the electron microscopical examination revealed that most promastigotes contained at least a small amount of kDNA. A few of the treated cells undergoing division contained two kinetoplasts--one devoid of kDNA and the other with a reduced amount of kDNA as seen in the electron micrographs.