Question
Biology Question on biotechnology
During the process of isolation of DNA, chilled ethanol is added to :
A
Precipitate DNA
B
Break open the cell to release DNA
C
Facilitate action of restriction enzymes
D
Remove proteins such as histones
Answer
Precipitate DNA
Explanation
Solution
Ethanol is much less polar than water. Adding it to the solution disrupts the screening charges exerted by water. The electrical attraction between phosphate and any positive ions (Na+)present in solution becomes strong enough to form a stable ionic bond and DNA precipitates. Ethanol precipitation is a widely used technique to purify, or concentrate nucleic acid.