During the process of isolation of DNA, chilled ethanol is added to :
- Break open the cell to release DNA
- Remove proteins such as histones
- Facilitate action of restriction enzymes
- Precipitate DNA
Answer
(4) Precipitate DNA
Solution
As per NCERT, the cells are broken open with enzymes (lysozyme, cellulase, chitinase), RNA is removed by ribonuclease and proteins by protease.
⇒ Purified DNA ultimately precipitates out after the addition of chilled ethanol; it can be seen as a collection of fine threads in the suspension (spooling).
∴ Chilled ethanol is added to precipitate DNA.
Answer: (4)