Angelo,

I saw this on the web.

Although oligonucleotides are stable in solution at 4°C for up to 2 weeks, Sigma recommends storage should be at -20°C. Repetitive freeze-thaw cycles should be avoided by storing as aliquots. For long-term storage, siRNA oligos should be dried. Oligonucleotides with fluorescent labels should be protected from light. Sigma guarantees its oligonucleotides for six months, when stored under the above conditions.

http://www.sigmaaldrich.com/life-science/custom-oligos/sirna-oligos.html

What is the stability of siRNA?

A duplex of RNA is significantly more resistant to nucleases than a single strand. However, maintaining sterile, RNAse free conditions is always recommended as a precaution. Dried pellets are stable at room temperature for 2-4 weeks, but should be placed at -20°C or -80°C for long term storage. Under these conditions, a dried siRNA will be stable for at least one year.

http://dharmacon.gelifesciences.com/resources/faqs/what-stability-sirna/

Best Whishes!

Thank  you, however I want to know how much I can store Lipofectamine : siRNA complexes! not siRNA themselves. I think you missunderstood the question, but thank you for the detailed answer !

I would keep them at 4c without freezing,  im sorry but have never stored them complexed.  They do well in the incubator for up to16h during transfections. 

I do hope it works out for you.

Best Wishes

Never encountered such situation. I would store such Lipo:siRNA complexes at 4°C and incubate at room temperature for 15-20 mins before transfection. Let us know what you got from such transfection experiment.

I contacted BioRad and they recommend freshly prepared complexes because when they tried transfecting with stored complexes they got very reduced efficiency. It is a weird situation but I will not risk wasting time on a sub-optimal transfection.

Thanks all to your answers!

Hello

For a short time ( 2 weeks - month) : at room temperature .

For a long time : at -20°C or -80°C .

Good Luck