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.

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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

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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

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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.

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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

The researchers changed the genome of Vibrio natriegens with a plasmid called MP6, which introduces errors into the genome and then screened the mutants for increased biosorption of rare earth elements.

From Science Daily • Dec. 18, 2023

Others returned to a practice of smuggling plasmids, circular molecules of DNA used to manipulate genes, from abroad after Addgene, the U.S. nonprofit plasmid repository and distributor, stopped shipping to Russia.

From Science Magazine • Nov. 9, 2023

They identified the presence of a new plasmid -- a small, circular DNA molecule -- in all epidemic V. cholerae samples tested since November 2018.

From Science Daily • Sep. 29, 2023

They also showed that although the improved Syn61Δ3 cells could exchange a plasmid engineered to use their modified genetic code, they could not share the plasmid with other bacteria.

From Science Magazine • Oct. 19, 2022

In molecular cloning with bacteria, a desired DNA fragment is inserted into a bacterial plasmid using restriction enzymes and the plasmid is taken up by a bacterium, which will then express the foreign DNA.

From Textbooks • Apr. 25, 2013