Single cell cloning of Leishmania parasites in purine-defined medium: isolation of drug-resistant variants.

A simple technique for the isolation of Leishmania donovani and Leishmania tropica promastigote clones derived from a single cell involves the use of semi-solid agar. Both species of Leishmania form discrete colonies at high efficiency in completely defined medium lacking serum. Visible colonies appear between eight and fourteen days. Viability of colonies transferred from semi-solid agar to liquid suspension culture is 100%. Using these techniques, we have isolated clonal populations of cells resistant to tubercidin and formycin b.