Plasmidin

Plasmidin is a term that appears in some scientific texts as a synonym or variant of plasmid, a small, circular, double-stranded DNA molecule that replicates independently of the host chromosome. In standard contemporary usage, plasmid refers to these extra-chromosomal elements found in bacteria, and also in some archaea, fungi, and algae. If the term plasmidin is used in a given source, its meaning may vary and there is not a single universally accepted definition.

Biological characteristics include carrying nonessential but advantageous genes, such as antibiotic resistance, metabolic enzymes, or virulence factors. Plasmids contain an origin of replication and often a partitioning system that helps ensure inheritance during cell division. They can exist in multiple copies per cell (high-copy) or in a single copy (low-copy) depending on regulatory elements and host factors. The host range of a plasmid determines which species can maintain it. Plasmids can be transferred between cells by mechanisms such as conjugation, transformation, or transduction, contributing to horizontal gene transfer.

Applications commonly associated with plasmids include their use as cloning vectors or expression vectors in molecular biology to study gene function, produce proteins, or deliver genes in research settings. Types of plasmids include those with antibiotic resistance markers for selection and shuttle plasmids capable of replication in multiple host species, though the exact features vary by construct and purpose.

Safety and regulation: Work with plasmids may be subject to biosafety guidelines and institutional approvals, particularly when resistance genes or virulence factors are involved.