How should QIAGEN Plasmid Purification Kits be stored and for how long?
FAQ ID -192

QIAGEN-tips and QIAfilter Cartridges should be stored dry and at room temperature (15–25°). They can be stored for at least two years without showing any reduction in performance, capacity, or quality of separation.

QIAGEN, QIAfilter, EndoFree, HiSpeed and Large-Construct Plasmid Kits should be stored at room temperature (15–25°). After adding RNase A, Buffer P1 should be stored at 2–8°C and is stable for six months. All other buffers and RNase A stock solution can be stored for two years at room temperature (15–25°).