A plasmid is a small, circular, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA. Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes.

Pancreatic cancer’s deadly resilience may be tied to extrachromosomal DNA, which allows tumor cells to rapidly adapt to ...

circular DNA molecules. Plasmids are used in molecular biology to build gene circuits because they are easy to modify and can boost gene expression. However, plasmid copy numbers can fluctuate ...

Janet Mertz’s work with simian virus 40 DNA during her graduate years was pivotal for developing DNA recombination as we now know it. In September 1970, Janet Mertz joined the biochemistry department ...

Circular DNA, thought to be an accidental byproduct, is borrowing the cell’s DNA repair mechanisms to copy itself DURHAM, N.C. -- Like its viral cousins, a somewhat parasitic DNA sequence called a ...

Bacteria commonly produce toxins that are lethal to themselves, but also produce the required antitoxins. These toxin-antitoxin (TA) systems may be useful in modifying bacteria for biotechnology ...

Prokaryotes, which include bacteria and single-celled microorganisms called Archaea, usually pass their chromosomal DNA on to their offspring asexually. In other words, a bacterial cell reproduces ...

In step 2, the gene fragment is integrated into a circular piece of DNA, called a plasmid, which is the main delivery vehicle into the cell and contains an antibiotic resistance gene for plasmid ...