Steps involved in Recombinant DNA Technology

Building a working recombinant DNA molecule is not one operation but a defined sequence of steps. First comes isolation: identifying and physically extracting the specific DNA fragment that carries the gene of interest - at this stage it is simply called 'the insert'. Second comes generation of the actual recombinant DNA molecule: the insert is spliced into a carrier molecule, the vector, which is chosen specifically because it can self-replicate once inside a living host cell - without that self-replicating property, the inserted gene would simply be lost rather than propagated. Third comes selection: the mixture of transformed (successfully carrying the rDNA) and untransformed host cells is grown up, and only the transformed cells are identified and allowed to multiply, which multiplies the rDNA molecule along with them. The end product of this whole process is one of two things, depending on what the experiment was designed to produce: either a large quantity of the recombinant DNA molecule itself, or a large quantity of the protein that the inserted gene encodes. There is also an important variant path: in situations where no vector is actually used, the gene of interest can instead be multiplied directly using the Polymerase Chain Reaction (PCR) - a common laboratory technique for ma …