Why am I getting multiple bands for my PCR results?

One of the likely causes of multiple bands in PCR is nonspecific primer annealing. To remedy this, you can try increasing the annealing temperature, increasing the concentration of MgCl₂, or decreasing the concentration of primer. Too many PCR cycles (more than 30) also has the potential to cause multiple bands due to the increased chance of error with each cycle. DNA contamination is another possible factor.