Question: 101 During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out
(1) Histones
(2) Polysaccharides
(3) RNA
(4) DNA
Answer: Option (4)
Explanation:
During purification of nucleic acids in recombinant DNA technology, DNA is separated from other cellular components.
DNA is insoluble in cold ethanol, whereas many other biomolecules remain dissolved.
Addition of chilled ethanol reduces the dielectric constant of the solution, which decreases the solubility of DNA.
As a result, DNA molecules aggregate and precipitate out of the solution.
Therefore, chilled ethanol is used to precipitate DNA during purification.