Does storing samples in RNAlater have advantages over freezing samples on dry ice or in liquid nitrogen?
Using samples that were stored in RNAlater is much easier than using frozen samples. Frozen samples must be ground to a powder and then the frozen powder must be transferred to a tube for homogenization. This procedure is laborious, messy, risks loss of sample, and perhaps most importantly, may lead to sample thawing, which can compromise RNA integrity. Samples stored in RNAlater are protected from RNases as long as the tissue remains in the solution, and they can typically be disrupted using the simpler methods appropriate for freshly collected samples (grinding in liquid nitrogen is only required for extremely hard or tough tissues such as bone or tumor tissue). Thus, in addition to making sample disruption easier, storage in RNAlater eliminates the risks of sample loss and mess due to transferring or thawing frozen powdered tissue.
