Replicates from a PCR amplification were left for varying numbers of days at room temperature. PCR product will not degrade when left at room temperature overnight, or even for 12 days. Results analyzed by DNA gel electrophoresis are shown in the figure below. For 12 replicate tubes, we ran 25 PCR cycles in a miniPCR and following cycling, we left the 12 tubes at room temperature, freezing replicates once a day for 12 consecutive days. The amplicon corresponded to a DNA control for a miniPCR Learning Lab. We amplified a 800 base pair fragment using EZ PCR Master Mix. We did a simple experiment to confirm this. If amplification is successful, the DNA in the tubes will be stable for a long time. So, do samples really need to be refrigerated immediately after PCR? Waiting for a reaction to finish can be inconvenient, and leaving a thermal cycler cooling overnight can severely reduce its useful life. This results in many users waiting for the reactions to finish so that they can place the tubes in a fridge or freezer, or programming thermal cyclers with an ‘infinite’ 4˚C hold. Many scientists and other PCR users believe that samples need to be refrigerated immediately after thermal cycling finishes. Truth #2: Extended cold holds will reduce your PCR machine’s lifetime Truth #1: DNA will be stable for days, even weeks inside a PCR tube Myth: PCR product needs to be refrigerated if left overnight in the thermal cycler

Pcr 800 amp