[Biological properties of promastigotes of Leishmania having undergone lyophilization].

Materials are presented of a comparative study of morphological and cultural properties and virulence of liophylized cultures of Leishmania tropica major after their rehydration or after a long passage on the NNN medium. Results of investigations of two initial strains and three substrains obtained after the recovery of liophylized cultures have shown that liophylization does not reduce essentially the initial strain virulence. The strains undergone liophylization and passed repeatedly on the NNN medium have a tendency to a quicker virulence reduction rate as compared to initial ones. The culture of promastigotes recultivated after liophylization does not differ from the initial one in the ranges of 1-7 passages in its morphology, mobility and ability to grow on the NNN medium.