storing large amounts of PCR mastermix beforehand - question (Aug/10/2009 )

Would it be fine to make up large amounts of PCR mastermix, but exclude Taq polymerase, DNA template, and primers? I want to store overnight in the freezer so I can just come in and start the next day or perhaps within that week. Just wondering the length of stability of the mastermix would be over time too?

claritylight on Aug 10 2009, 08:02 AM said:

I have stored such mastermixes (even including Taq) overnight at 4'C, without any appreciable reduction in PCR products. I have not been so daring as to store it in -20 or for prolonged periods of time.

I guess it also depends upon the robustness of your product specific PCR. But let us know your insights if you try this out at your expense!

I do not and have never stored any mastermixes for prolonged periods of time. I always prepare my mastermix just before I am going to do my PCR. I guess it shouldn't do any harm to store mastermix overnight at -20 though, so long as you ensure you spin down everything and mix them well before you use it for your PCR.

Do let us know how things go for you. =)

I think I may be missing something: if your PCR master mix does not contain Taq or primers, then why prepare it ahead of time? I guess you can mix the dNTPs and reaction buffer ahead of time, yet I do not see the advantage of this since you still would need to add the Taq and primers before using it.