PCR Hint #2 Store PCR reagents in fridge

PCR Hint #2 - Don't freeze thaw your PCR reagents

One thing that many people do is store their PCR reagents (ie buffer, MgCl, dNTP, primers, DNA polymerase) frozen at -20 deg C and then thaw them out when they need to set up a PCR. The problem with this approach (other than the time it takes to thaw everything out) is it is very damaging to the reagents. Once you have been through 5 -10 freeze-thaw cycles it becomes highly likely that one of you reagents is dead (most likely the dNTPs).

A better approach is thaw out the large stock once and create a set of reagent aliquots (about a weeks worth) in multiple tubes and store these. This way you can take out a fresh batch every Monday and keep it in the fridge. The reagents will last fine for a week at 4C and this way you don't need to subject them to freezing and thawing. It also has the nice side effect of reducing PCR contamination problems because you are using a fresh batch of reagents once a week.

Daniel Tillett
Nucleics Support



Edited 1 time(s). Last edit at 12/20/2006 06:32PM by nucleics.

I have to agree with daniel here - I have been doing something similar for years. I don't bother making small stock solutions, I just keep all my pcr solutions in the fridge.