Question

The important parameters for precise annealing of the probe and the subsequent washing don’t include ___________

(a) Size of the probe

(b) Proportion of only A

(c) Ionic concentration of hybridization buffer

(d) Other agents which alter the base pairing

I have been asked this question in a national level competition.

Question is taken from Database Screening and Screening by Nucleic Acid Hybridisation in section Screening Libraries of Genetic Engineering

Answer 1

The correct answer is (b) Proportion of only A

To elaborate: The probe should anneal precisely and the parameters which decide these are size of the probe, proportion of all A, G, T and C. Ionic concentration of hybridization buffer and other agents such as formamide which alter base pairing. These parameters define the maximum temperature at which probe and target DNA bind fully.