Answer:
An annealing temperature that is too low
Step-by-step explanation:
The annealing temperature (Ta) chosen for pcr relies directly on length and composition of the primers. Generally, you should use an annealing temperature about 5°C below the Tm of your primers. An optimal annealing temperatures give the highest product yield of the correct amplicon. An amplicon is a piece of DNA or RNA that is the source and/or product of amplification or replication events. It can be formed artificially, by either using various methods in polymerase chain reactions (PCR) or ligase chain reactions (LCR), as well as, naturally through gene duplication.