question_answer

Explain the role of following in the biotechnology

(i) Restriction endonuclease

(ii) Gel-electrophoresis

(iii) Selectable markers in pBR322.

Answer:

(i) Restriction endonuclease The enzymes that act on specified length of a DNA by binding at the specific recognition sequence. It cuts both the double, strands of DNA, at the sugar phosphate backbones, a little away from the centre of palindromic sites in between the specific sequence or points.

(ii) Gel, electrophoresis It is used to separate the DNA fragments generated by the restriction endonuclease on an agarose gel. The fragments get separated according to their size under the influence of an electric field.

(iii) Selectable marker These markers in cloning vector help in identifying and selecting the recombinants and eliminating the non, recombinants, e.g. ampicillin and tetracycline resistant genes in E. coli.