Question

Why can't we use room temperature ethanol in dna extraction?

Answer 1

ice cold ethanol helps in increasing the yield of dna. the main reason behind using ice cold ethanol has not been explained properly anywhere but one of the reason for its use can be as that the temperature decreases, there is more and more precipitation. one more reason for using ice cold ethanol can be that the enzymes dnases, like other enzymes are temperature sensitive therefore dnases are not active when the temperature is too low. since these organisms are involved in dna lysisand degradation, reduction in this enzymes activity will lead more amount of pure dna.

Answer 2

DNA is sensitive to temperature. In normal or room temperature the enzymes like DNAse may become active and split DNA apart.

In low temperatures all the activity of enzymes lowers or enzymes become inert. So the structure of DNA is preserved.

Ethanol at low temperatures aids quick precipitation of DNA so that it can be easily extracted with out structural splits.