Plasmids are (or mimetic) DNA molecules outside the nucleus, present in the cytoplasm (except in yeast, where the 2 μm plasmid is present in the nucleus), with the ability to replicate autonomously, allowing them to maintain a constant copy number even in daughter cells, and to express the genetic information they carry, as closed-loop double-stranded DNA molecules. It is widely found in living organisms, ranging from bacteria, actinomycetes, filamentous fungi, macrofungi, yeast to plants and even in the human organism. In terms of molecular composition, there are DNA plasmids as well as RNA plasmids. In terms of molecular conformation, there are linear plasmids and cyclic plasmids: their phenotypes are also diverse.
Bacterial plasmids are the most used vectors in genetic engineering. Plasmids are not essential for bacterial growth and reproduction, and can be lost on their own or eliminated by artificial treatments, such as heat and UV light. Plasmids carry genetic information that can confer certain biological traits to the host bacterium and facilitate the survival of bacteria under specific environmental conditions. A certain target gene fragment is recombined into a plasmid to constitute a recombinant gene or recombinant. This recombinant is then transferred into the recipient cell by microbiological transformation techniques, so that the target gene in the recombinant can be propagated or expressed in the recipient bacterium, thus changing the original trait of the host cell or producing a new substance. Whole plasmid sequencing, which is based on second-generation high-throughput sequencing technology, is used to build a library to sequence the whole genome of the plasmid, and the sequencing data are analyzed for sequencing depth, GC content, and full sequence assembly of the plasmid using bioinformatic analysis. In terms of years' professional experience in this field, Creative Biogene can provide you with the most affordable and high-quality complete plasmid DNA sequencing services.
Figure 1. The process of complete plasmid DNA sequencing.