Gram-negative bacteria Conjugation is the mating of 2 bacterial cells during which DNA is transferred from the donor to the recipient cell. The mating process is controlled by an R plasmid which carries the genes for the proteins required for conjugation. After enzymatic cleavage of the R factor DNA, one strand is transferred across the conjugal bridge into the recipient cell. It allows drug-resistant plasmids such as R to spread. It allows genetic exchange by Hfr mating.
Bacteria also can acquire new metabolic capabilities.
The reaction products were analyzed by electrophoresis on an agarose gel. The predicted sulfametoxazole resistance PCR product is 1 kb. The sulfametoxazole resistance gene can be amplified from DNA of the S. typhi and mixed cultures. This result is expected, since S. typhi is present in both cultures and this organism contains the conjugative plasmid carrying the sulfametoxazole resistance gene. This is an important control for PCR, since this procedure will produce a product from small amounts of contaminating DNA from the environment.