If the extension temperature was eliminated altogether from

If the extension temperature was eliminated altogether from the thermocycler, what would happened to our Alu PCRs? [Hint: the size of your fragments is important]

Solution

Not much dierence can be seen with and without the extension step.

As the Alu fragments are smaller in size, extension of the PCR product will take place at the annealing temperature but it will be slower because the optimal temperature for the processivity of taq polymerase is 72 degrees. May be bigger DNA fragments (<500bp) may not get amplified but it is highly likely that smaller fragments (<500) are amplified.