Why is a DNA pellet washed?

Correct answer: To remove impurities like salts and alcohol

The direct answer is A: the DNA pellet is washed to remove impurities such as salts and residual alcohol. During DNA precipitation, DNA collects as a pellet, but some salts, buffer components, and alcohol can remain around it. A suitable wash, commonly involving alcohol under the protocol, helps remove these contaminants. The reasoning is: precipitation concentrates DNA; unwanted soluble chemicals may remain with the pellet; washing dissolves or carries away many of them; careful drying then helps remove remaining wash liquid; the DNA is finally redissolved for later work. Option A is correct because clean DNA performs better in downstream reactions. Option B is wrong because washing does not cut DNA; cutting requires restriction enzymes or another fragmentation method. Option C is wrong because DNA is not converted into protein by washing; protein synthesis is a cellular process involving RNA and ribosomes. Option D is wrong because a DNA pellet is not a living cell, so washing cannot make a cell alive. Excessive washing or incomplete drying can cause problems, so the protocol must be followed carefully. Memory cue: “wash the pellet to wash away contaminants, not to change the DNA.”