Can RNAlater Stabilization Reagent be used to store previously isolated RNA?
FAQ ID -337

We do not recommend to store previously isolated RNA in RNAlater Stabilization Reagent, since it will be very difficult to recover isolated RNA from it. Purified RNA can be stored at -20°C or -70°C in sterile RNase-free water. Under these conditions, we found no detectable RNA degradation after 1 year of storage.