See Also: Plasmid(medicine)
plasmid(dictionary)
plasmid(encyclopedia)
f plasmid(medicine)
R plasmid(medicine)
Ti plasmid(medicine)
RNA plasmid(medicine)
conjugative plasmid(medicine)
transmissible plasmid(medicine)
supercoiled plasmid(medicine)

plasmid (sh)




Genetic element not contained within a chromosome.

It occurs in many bacterial strains. Plasmids are circular DNA molecules that replicate independently of the bacterial chromosome. They are not essential for the bacterium but may give it a selective advantage. Some plasmids determine the production of proteins that can kill other bacteria; others make bacteria resistant to antibiotics. Plasmids are extremely valuable tools in the fields of molecular biology and genetics, specifically in the area of genetic engineering.