In: Biology
PCR can be utilized to generate a large quantity of a specific DNA fragment. The following questions refer to a PCR reaction designed to amplify the DNA helix below.
Region 1 Region 2
5’ GCTAGCTGTGGCTTAATATAGCCCGCAGTAGCGT 3’
b. While mixing up the PCR reaction mix, you accidentally add too little of the concentrated buffer, thus producing a lower than anticipated ion concentration. To compensate, you should (INCREASE/DECREASE/NOT ALTER) the denaturation temperature. Which of the explanations below best supports your answer?
A. There is going to be increased repulsion between the strands.
B. There is going to be decreased repulsion between the strands.
C.There is going to be charge associated with the DNA bases.
b. DNA denaturation refers to the breaking of hydrogen bonds between the bases of a double-stranded DNA molecule to generate two single strands.
During mixing up the PCR reaction mix, accidentally added too little of the concentrated buffer, produced the lower ion concentration than the anticipated ion concentration. To compensate for this, we should decrease the denaturation temperature.
As ion concentration is low, less ion is present to shield the negative(-ve) charge on the phosphate(P) backbone. That means there will be more repulsion (due to less shielding effect of ions) and less heat will be required to denature the DNA.
The best supportive explanation is A. There is going to be increased repulsion between the strands.