Final answer:
To address non-specific amplification in PCR, increasing the annealing temperature is usually recommended. If the temperature is too high, primers may not bind efficiently, leading to reduced yield or failure to amplify the target DNA sequence.
Step-by-step explanation:
Non-specific amplification during PCR can often be remedied by optimizing the conditions under which the PCR is carried out. This includes adjusting the temperatures for the denaturation, annealing, and extension phases, as well as the duration of these steps. When encountering non-specific amplification, the recommended action from the provided options would be to increase the annealing temperature.
This would help increase the specificity of primer binding, thus reducing the chances of non-specific bands due to primer-dimer formations or primers binding to unintended sites on the DNA template. However, if the annealing temperature is already optimized, one might consider increasing the annealing time to allow more time for the correct primer-DNA binding, but doing so could also allow non-specific bindings if the conditions are not specific enough.
If a PCR protocol was incorrectly set with an annealing temperature that is higher than intended, this could lead to insufficient or no annealing of primers to the target DNA sequence, causing a lack of amplification. In the specific scenario where the annealing temperature was set to 65°C instead of the intended 50°C, the primers may not bind efficiently to the target DNA, leading to a reduced yield or failure to amplify the desired product.