Give an account of the Blue-White Method of selection of recombinants.

Recombinant DNA technology (RDT) involves several steps in a specific sequence that allows alteration of genetic material like: Isolation of DNA Fragmentation of DNA by restriction endonucleases Isolation of the desired DNA fragment Ligation of the DNA fragment into a vector Transferring the recombinant DNA into the host Culturing the host cells in a medium at a large scale Extraction of the desired product The blue-white screen is a method of selection or screening technique that allows for the rapid and convenient detection of recombinant bacteria in these experiments. Recombinant DNA (altered DNA) is inserted into a competent host cell viable for transformation. The transformed cell is then grown in the presence of X-gal. A cell transformed with vectors containing recombinant DNA will produce white colonies, cells transformed with non-recombinant plasmids grow into blue colonies. Such screening is usually performed using a suitable bacterial strain, but other organisms such as yeast may also be used.