plasmid

American  

[plaz-mid] / ˈplæz mɪd /

noun

Microbiology.

1. a segment of DNA independent of the chromosomes and capable of replication, occurring in bacteria and yeast: used in recombinant DNA procedures to transfer genetic material from one cell to another.

---

plasmid British  

/ ˈplæzmɪd /

noun

1. a small circle of bacterial DNA that is independent of the main bacterial chromosome. Plasmids often contain genes for drug resistances and can be transmitted between bacteria of the same and different species: used in genetic engineering

---

plasmid Scientific  

/ plăz′mĭd /

1. A small, circular unit of DNA that replicates within a cell independently of the chromosomal DNA and is most often found in bacteria. Certain plasmids can insert themselves into chromosomes in places where there is a common sequence of nucleotides. Plasmids contain a few genes, which usually code for proteins, especially enzymes, some of which confer resistance to antibiotics. Plasmids are used in recombinant DNA research, especially to transform bacterial cells.

2. See more at transformation

---

plasmid Cultural  

1. A circular bacterial DNA, sometimes used as a vector for gene insertion or genetic engineering. Plasmids are often the site of genes that code for resistance to antibiotics.

---

Etymology

Origin of plasmid

First recorded in 1950–55; plasm- + -id ³

Compare meaning

How does plasmid compare to similar and commonly confused words? Explore the most common comparisons:

• plasmid vs. chromosome

Example Sentences

One reason for the gene’s rapid spread: Klebsiella is adept at grabbing plasmids—extrachromosomal DNA–containing resistance genes directly from other bacteria.

From Science Magazine

Bacteria can spread resistance genes to each other through plasmids.

From Science Daily

Some of the drivers of evolution in microbes are even smaller DNA structures called plasmids that infect, exist and replicate inside a bacterium in ways that can change bacterial DNA.

From Science Daily

Currently, when researchers place a plasmid into E. coli, they can create many copies to test several variants.

From Science Daily

The scientists have considered regulatory measures by developing a biocontainment strategy to avoid the use of elements that generate regulatory concerns such as mobile genetic elements, plasmids or antibiotic resistance.

From Science Daily