What is the stability of siRNA lyophilized and resuspended?
Lyophilized siRNAs are stable for one year at -20C in a constant temperature freezer. If it is fluorescently labeled and stored in the dark, it should be stable for six months at -20.
If its lyophilized and kept sealed, it's stable for months at room temperature.
Once the siRNA is resuspended in nuclease-free buffer, it should be stable at -20 (in the dark if fluorescently labeled) for at least six months assuming it is kept RNase-free. It is best to store resuspended RNA in aliquots to reduce the effects of any accidental RNase contamination.