plasmid /ˈplæzmɪd/ noun1 •A loop of double-stranded DNA that is separate from — and replicates independently of — the chromosomes; such loops are most commonly found in bacteria, but they are also sometimes found in archaeans and eukaryotic cells, and they are used in genetic engineering as a vector for gene transfer.This is how the F (for "fertility") plasmid, which forms the basis of a lot of classical E. coli genetics, is transferred from one cell to another. — 1995 formsplasmids
