Molecular Pathology- Miscellaneous I
Question No. 12. The Answer is: (A) Control of specificity of hybridization.
Discussion: Stringency is generally controlled by raising or lowering the temperature, and/or the salt concentration, and the concentration of formamide of the hybridization solution or wash buffers. High stringency conditions (high temperature and low salt) promote denaturation (dissociation) of nucleic strands, while low stringency (low salt and low temperature) promotes annealing or stabilization of nucleic acid hybridization. The higher the stringency the higher the specificity of the hybridization, the lower the stringency the more non-specific the reaction will become. The wash steps in nucleic acid hybridization (on membrane or in situ in cells or tissues) generally involve a sequence of steps with gradually increased stringency.