[The effect of new antimicrobial preparations used in combination with complete gnotobiotic isolation on the survivability and intestinal microflora of total-body irradiated mice].

The aim of these investigations was the study of the effect of different antimicrobial preparations on the survival rate and intestinal microflora of mice with experimental acute radiation sickness. These investigations revealed that the survival rate of the animals increased 3.1 times with the use of Supramycin, 2.

[Cloning the genetic determinant of alpha-hemolysin and obtaining a series of insertional mutations in this determinant by the transposon Tn1000].

Functionally active genetic determinant of alpha-hemolysin was cloned. Hemolytic plasmid pHly195 was used as a donor of the determinant and pBR322 plasmid served as recipient. Cloning was done with a help of HindIII restriction endonuclease.

[Translocation of ampicillin transposon Tn1 in Escherichia coli cells during sexual reproduction].

The efficiency of Tn1 transposition has been shown to increase considerably in course of bacterial conjugation. Usually, the frequency of Tn1 transposition from plasmid pSA2001, a derivative of RP4, into the chromosome never exceeded 0.1% per cell.