DNA precipitation out of a mixture of biomolecules can be achieved by treatment with
Answer: (B) Chilled ethanol. Answer: (B) Chilled ethanol Solution: During isolation of genetic material, after the cell is broken open and RNA/proteins are removed (by ribonuclease and protease respectively), the purified DNA precipitates out of the mixture upon addition of chilled ethanol, seen as fine threads in suspension.
- A.Isopropanol
- B.Chilled ethanol✓
- C.Methanol at room temperature
- D.Chilled chloroform
Correct Answer
(B) Chilled ethanol
Solution & Explanation
Answer: (B) Chilled ethanol Solution: During isolation of genetic material, after the cell is broken open and RNA/proteins are removed (by ribonuclease and protease respectively), the purified DNA precipitates out of the mixture upon addition of chilled ethanol, seen as fine threads in suspension. Chilled ethanol is the reagent NCERT specifies for this precipitation. NCERT Reference: Ch 9, p.171, line(s) 40-41 — "purified DNA ultimately precipitates out after the addition of chilled ethanol."