Plasmid is a kind of DNA molecule that is found in bacterial DNA, and it is mostly used for genetic engineering.
Many bacteria have these small circular objects that are found inside the cytoplasm of the bacteria, and they are called as plasmids. Although they are found in the bacterial cell, they are different and separate from the chromosomal DNA and carry the genetic information of the bacteria. Hence, plasmids are normally used by scientists and researchers that explore plasmids to understand the genetic information of a particular bacterium. They also use them for gene cloning of the bacteria for research purpose. In some bacteria, many plasmids are present at one time in one single bacterium.
Plasmids are also found in archea and eukarya apart from bacteria, and they are not considered as a form of life, although some researchers believe it that way. Plasmids are also known as naked DNA, and therefore, it does not require any mechanism for horizontal gene transfer. They are sometimes strong enough to resist certain antibiotics, and they can allow bacteria to repair their elemental nitrogen and save them from nutrition deprivation. However, plasmids are most commonly used in genetic engineering where they are used to multiply particular genes as they have genes that can quickly duplicate themselves.
In genetic coding, some of the plasmid cells are first isolated from the rest, and are treated with enzymes that will break down the bacterial wall. Scientists then separate the chromosomal DNA, and only the isolated plasmid is left out. Genes that are required for multiplication are now inserted into the plasmids, and the gene coding process begins instantly. Soon bacteria tries to copy the plasmid, and soon you will find that there are more than 200 to 300 copies of single plasmid in that bacteria and this replication process happens after every 20 to 30 minutes.
