NEET Class neet Answered

when the transformant having recombinant gene will be grown in tetracycline medium then it will die. in this way can distinguish transformant from non-transformant. but transformant have already died then how they will be further used in the production of products?

Asked by rohitraman1115 | 24 Jan, 2020, 03:34: PM

Expert Answer

Some genes called selectable markers help in selecting those host cells which contain the transformed vectors and eliminate the non-transformants.
Transformation is a process through which a piece of DNA is introduced in a host bacterium.
Generally, the genes encoding resistance to antibiotics such as tetracycline, ampicillin and kanamycin are useful selectable markers for E. coli.
Plasmid pBR322 has two resistance genes—ampicillin resistance (amp^R) and tetracycline resistance (tet^R)—which are considered useful for selectable markers.
Insertion of the DNA fragment into the plasmid using enzyme PstI or PvuI places the DNA insert within the gene amp^R, which makes amp^R non-functional.
Bacterial cells containing such a recombinant pBR322 will be unable to grow in the presence of ampicillin but will grow on tetracycline.
These recombinants can then be used for the production of useful products.