forgotten the kits at room temperature - (Jul/16/2014 )

Hi,

My friend forgot my gene array plates (96 well) and cDNA kits at room temperature nearly 1 week. Are they stable and suitable for PCR?

Depends almost entirely on what buffer, if any, they are stored in. DNA stored in TE at room temperature is stable for months or years. In pure water, or with magnesium ions present, it degrades rather rapidly. Use TE when you elute DNA.

plate wells include gene spesific primers and they are lyophilized. I use SYBR green master mix to do PCR.

cDNA kit is the following:

http://www.genecopoeia.com/product/qpcr-cdna-synthesis-kit/

Lyophilized DNA in your plate should be just fine. I would not trust a PCR master mix. If you wanted to attempt to use it, you might rescue it you could try it, and if it fails, add dNTPs, which is the thing most likely to go bad. I would just toss it, however, especially if I were doing something important.

Thank you

phage434 on Wed Jul 16 15:42:23 2014 said:

Depends almost entirely on what buffer, if any, they are stored in. DNA stored in TE at room temperature is stable for months or years. In pure water, or with magnesium ions present, it degrades rather rapidly. Use TE when you elute DNA.

Out of curiosity: what if you use MQ water or demi water? Is this also as good as TE to store DNA in?

No! milliQ water takes CO2 from the air, and acidifies rapidly -- there is nothing buffering at neutral (or slightly basic) pH. Similarly, slight contamination from tubes, fingers etc. puts small amounts of magnesium ions into solution. These would be chelated by the EDTA in TE, but not in pure water. TE is really designed for this. If you are concerned about downstream use (very rarely a problem) then use a lower concentration of EDTA. Instead of 1 mM, go to 0.2 or even 0.1 mM, which will have negligible effect on magnesium concentrations in enzyme buffers and other reactions, but will still protect against modest free magnesium ion concentration.