[Determination of DNA content in individual Vibrjo cholerae cells by using flow cytofluorimetry method: comparative analysis of inhomogeneity in cells of strains with various biological properties].

Aim: Comparative analysis of DNA content in individual cells of Vibrio cholerae strains with various biological properties.

Materials And Methods: 24-hour agar cultures of 2 avirulent (lacking cholera toxin gene) and 2 virulent strains and their subcultures obtained by cultivation in 1% peptone water for 1, 3 and 5 hours were studied. DNA of the killed bacteria was dyed by a mixture of ethidium bromide and mitramycin.

[Determination of DNA content in individual Yersinia pestis cells by using flow cytofluorimetry method: comparative analysis of inhomogeneity in cultures of strains with various biological properties].

Aim: Comparative analysis of Yersinia pestis strains with various biological properties by DNA content in individual cells.

Materials And Methods: Virulent strain 231, avirulent strain KM 260 (12) [231], that is its isogenic (no-plasmid) derivative, and vaccine strain EV NIIEG were used. 48-hour agar cultures of the studied strains reproduced at 28 degrees C and their subcultures obtained by cultivation of the initial cultures by aeration on liquid nutrient medium from 37 degrees C were prepared.