Plasmid DNA is a small, circular, double-stranded DNA molecule found in bacteria and some other organisms. It exists independently of the chromosomal DNA and can replicate autonomously within the host cell. Plasmids often carry genes that confer advantageous traits such as antibiotic resistance or the ability to metabolize certain compounds. They are widely used in molecular biology research as vectors for cloning genes, expressing proteins, and studying gene function. Additionally, plasmid DNA serves as a crucial tool in genetic engineering, facilitating the manipulation and transfer of genes between different organisms. https://www.dnatestingexperts.com/what-is-plasmid-dna-exploring-the-functions-structure-and-differences-from-chromosomal-dna/