Question

At what temperatures the hybridization and washing of the DNA probes should be carried out?

(a) At melting temperature

(b) At a temperature lower than the melting temperature

(c) At a temperature higher than the melting temperature

(d) At 100 degrees

This question was addressed to me in unit test.

My doubt stems from Database Screening and Screening by Nucleic Acid Hybridisation in portion Screening Libraries of Genetic Engineering

Answer 1

Right answer is (b) At a temperature lower than the melting temperature

Easiest explanation: The hybridization and washing of the DNA probes should be carried out at a temperature below than the melting temperature. It is so because if it is carried out a temperature lower than the melting temperature, some amount of mismatch is allowed. Melting temperature depends on the composition of the probes.