Preserving RNA Before Isolation
Appropriate storage of cells or tissue samples prior to RNA isolation is critical for preservation of intact RNA within those samples. RNAlater is an aqueous solution designed specifically to maintain RNA integrity during storage of fresh tissue and cell samples. Below are some commonly asked questions regarding RNAlater®
1) How do I use RNAlater to store my tissue/cell sample?
- For fresh tissue, simply cut samples to a maximum thickness of 0.5 cm in any one dimension and submerge in 5 volumes of RNAlater.
- Cultured cells should be pelleted, resuspended in a small volume of PBS, then mixed with 5-10 volumes of RNAlater.
- Once in RNAlater, samples can be stored for up to 1 day at 37°C, 1 week at 25°C, 1 month or more at 4°C, and long-term at -20°C or -80°.
2) Does storing samples in RNAlater have advantages over freezing samples on dry ice or in liquid nitrogen?
3) Has RNAlater been tested with my tissue or with blood samples?
4) Which downstream applications can be used with tissue stored in RNAlater?
Note: RNAlater is not recommended for use with tissues that will be sectioned using a cryostat.
5) How can I ship my sample in RNAlater?
6) Can I add RNAlater to samples that are already frozen?
- A different product, RNAlater®-ICE, is used with samples that are already frozen. RNAlater-ICE transitions tissue from a frozen to a non-frozen state. The frozen tissue is simply placed in RNAlater-ICE and left at -20°C overnight. Treated tissues can then be used directly in standard homogenization and isolation protocols and processed like fresh tissue.
- RNAlater and RNAlater-ICE provide flexibility for sample collection and storage, and help ensure that high quality RNA is preserved in samples. Both are available in a variety of convenient sizes.