[medhahegde]

Recombinant DNA (rDNA) technology is an area of molecular biology in which researchers edit DNA to create novel synthetic molecules, which are usually designated as chimeras. The isolation and manipulation of genes in rDNA technology facilitates more accurate genetic analysis as well as its useful applications in medicine, agriculture, industry and medicine.

The initial step in the transformation procedure of rDNA technology involves inserting a piece of DNA into a suitable vector. A molecule of DNA that carries foreign DNA into a host cell (generally yeast or bacteria), where it replicates, generating numerous copies of itself together with the foreign DNA, is known as a cloning vector. The unique features that are essential to be a cloning vector requires presence of specific sequences that allows the propagation of the vector in bacteria or yeast, presence of a cloning site to insert the foreign DNA (most of the handiest vectors contain a site that can be cleaved by many of the restriction endonucleases) and a process to select for bacteria or yeast harbouring a vector with foreign DNA (this is typically done by selectable markers for various drug resistance). The various types of cloning vectors utilized are Plasmids, Phages, Cosmids, Bacterial Artificial Chromosomes (BAC) and Yeast Artificial Chromosomes (YAC).

The genetic modifications in gene therapy can be carried out in vitro or straightforwardly in vivo by utilizing vectors that are capable of genetic transfer. Presently the most efficient procedure for gene transfer is to utilize viral vectors. They act by infecting the target cell and deliver the therapeutic gene by their usual biological phenomenon. Viral vectors that are utilized in gene therapy must be incapable to replicate and should have no lytic ability. A virus that carries an altered or foreign gene is termed as a viral vector. Some of the viruses that are utilized as vectors in rDNA technology include Retroviruses, Adenoviruses, Parvovirus, Herpes virus and Poxviruses.