Q. DNA precipitation out of a mixture of biomolecules can be achieved by treatment with
(a) chilled chloroform
(b) isopropanol
(c) chilled ethanol
(d) methanol at room temperature.
Answer (c) : In order to cu t the DNA with restriction enzymes, it needs to be in pure form, free from other macromolecules. Since the DNA is enclosed by the membranes, we have to break the cell open to release DNA and other macromolecules like RNA, proteins, polysaccharides and lipids. It is obtained by treating the bacterial cells/plant or animal tissue with enzymes. Other molecules are removed by appropriate treatments and purified DNA ultimately precipitates out after the addition of chilled ethanol.
