Since, DNA molecules are hydrophillic, they cannot pass through cell membranes. For recombinant DNA to be integrated into vector or host genome it is necessary for the DNA to be inserted in the cell. Therefore, making the host cells competent is necessary in biotechnology experiments.
The two ways by which cells can be made competent to take up DNA are: (i) Chemical action By increasing concentration of divalent cation, calcium, thereby increasing the efficiency of DNA entering through pores in cell, wall. (ii) Heat shock treatment Incubating the cells with recombinant DNA on ice, followed by brief treatment of heat at 42 °C and again putting them back on ice.
Why is making cells competent essential for biotechnology experiments? List any two ways by which this can be achieved.
Answers
Amit Kanwar
Since, DNA molecules are hydrophillic, they cannot pass through cell membranes. For recombinant DNA to be integrated into vector or host genome it is necessary for the DNA to be inserted in the cell. Therefore, making the host cells competent is necessary in biotechnology experiments.
The two ways by which cells can be made competent to take up DNA are:
(i) Chemical action By increasing concentration of divalent cation, calcium, thereby increasing the efficiency of DNA entering through pores in cell, wall.
(ii) Heat shock treatment Incubating the cells with recombinant DNA on ice, followed by brief treatment of heat at 42 °C and again putting them back on ice.