What happens to the PCR product if the [Mg2+] concentration is optimal?

When the concentration of magnesium ions (Mg2+) in a PCR reaction is optimal, the result is a high yield of the desired PCR product. Magnesium ions play a crucial role in the PCR process as they are essential for the activity of DNA polymerase, the enzyme responsible for synthesizing new DNA strands. At optimal concentrations, Mg2+ facilitates the binding of the DNA polymerase to the DNA template and helps stabilize the DNA-DNA interactions required for successful annealing of primers and extension of the new DNA strands.

A high concentration of Mg2+ can lead to increased nonspecific binding, but when the concentration is just right, it balances the efficiency of the amplification without introducing excessive background noise or unwanted products. Therefore, with the right amount of magnesium present, the PCR can efficiently replicate the target DNA, resulting in a significant yield of the specific product. This highlights the importance of optimizing reagent concentrations in PCR to obtain the best results.