Growth and transformation of Trypanosoma danilewskyi in a liquid medium.

The complex liquid medium L4NHS has proved suitable for obtaining trypomastigote-rich suspensions of the fish parasite Trypanosoma danilewskyi. Growth of T. danilewskyi strains in the medium has been characterized in test tube cultures at 25 degrees C. The cultures with an initial cell density of 1 x 10(5) x ml01 grew exponentially for 3 days with an average generation time of 15 h 17 min (strain BD) and 14 h 25 min (strain BZ). Both strains remained in the stationary phase for another 7-10 days. Total growth amounted to 1.3-1.6 x 10(7) cells x ml-1. The trypanosomes in culture were polymorphic (epimastigotes, broad trypomastigotes, slender trypomastigotes). The succession of the epimastigote and trypomastigote stages was dependent on the growth phase. The trypomastigotes of the strain BD from 300 ml Erlenmeyer flasks containing 40 ml of medium. Suspensions of trypanosomes from these cultures proved to be useful antigenic substrate in a determination of anti-ds-DNA antibodies by the kinetoplast immunofluorescence assay.