• Immediate RNase inactivation
• Freedom from liquid nitrogen and freezers
• Eliminates freezing and grinding
• Perfect for field collection
• Flexible tissue storage
• Compatible with most RNA isolation procedures including all of Ambion's RNA isolation kits

RNAlater is an aqueous, non-toxic tissue storage reagent that rapidly permeates tissues to stabilize and protect cellular RNA. RNAlater eliminates the need to immediately process tissue samples or to freeze samples in liquid nitrogen for later processing. Tissue pieces can be harvested and submerged in RNAlater for storage without jeopardizing the quality or quantity of RNA obtained after subsequent RNA isolation.

Revolutionary reagent eliminates the need to immediately freeze samples to preserve RNA

Make Time Stand Still with RNAlater

Once saturated in RNAlater, tissues can be removed, dissected or weighed at room temperature, then returned to RNAlater for continued storage. RNAlater-treated tissues archived at -80°C can be subjected to 10 freeze/thaw cycles without affecting the quality of subsequently isolated RNA (Figure 1). Samples stored in RNAlater can be shipped on wet ice or even at room temperature if shipped overnight. Figure 2 shows ribonuclease protection assay data using RNA from tissue stored in RNAlater.

Figure 1. RNA Stability of RNAlater Treated Tissues After Multiple Freeze/Thaw Cycles. Mouse heart and liver were dissected and placed in RNAlater. The tissues were frozen on dry ice and thawed at room temperature for the indicated number of cycles. RNA was isolated using RNAWIZ™, electrophoresed on a 1% formaldehyde/agarose gel, ethidium bromide stained and photographed.

Figure 2. Ribonuclease Protection Assay Using Mouse Tissues Stored in RNAlater. Tissues were stored in RNAlater for 1 or 4 weeks at 4°C. RNA was isolated from each tissue and analyzed using the RPA III™ Kit.

How do I use RNAlater?

Cut tissue to be less than 0.5 cm in at least one dimension and simply submerge it in 5 volumes of RNAlater (e.g. a 0.5 g sample requires about 2.5 ml of RNAlater). Small organs such as rat kidney, liver and spleen can be stored whole in RNAlater. Resuspend pelleted cells in a small amount of PBS before adding 5-10 volumes of RNAlater. Samples can be stored at 4°C for one month, at 25°C for one week or at -20°C indefinitely. Archive RNAlater-treated tissues at -20°C.

For RNA isolation, simply remove the tissue from RNAlater and treat it as though it was just harvested. Most tissues can be homogenized directly in lysis buffer, although harder tissues such as bone may require freezing in liquid nitrogen and grinding.

Is RNAlater compatible with my system?

RNAlater has been tested on a variety of mammalian tissues, plants, E. coli, Xenopus, fish and Drosophila. It has been successfully used with all of Ambion's RNA isolation kits (Figure 3) including RNAqueous™, ToTALLY™ RNA, RNA WIZ™ and Poly(A)Pure™, as well as TRI^® Reagent (MRC). Other commercial RNA isolation kits and standard RNA isolation protocols are also compatible with RNAlater.

Figure 3. Compatibility of Various RNA Isolation Methods with RNAlater. Freshly dissected whole mouse liver and heart were placed in RNAlater and stored at 4°C for three days. RNA was isolated from equal mass amouts of each tissue using Ambion's ToTALLY™ RNA, RNAqueous™ or Poly(A)Pure™ Kits.

Does RNAlater preserve the histology of tissues?

Recent research by Drs. Scott Florell and Sancy Leachman at the Huntsman Cancer Institute [Florell et al. (2001) Mod Pathol 14:116-128] demonstrate that RNAlater does preserve the histology of tissues. A blinded study was performed, in which 2 pathologists compared human tissue sections that were either immediately processed for histology (fixed in formalin and embedded in paraffin, or frozen sectioned) to samples stored in RNAlater, rinsed, and then processed for histology. Their results indicate that morphological detail and staining characteristics were identical for the 2 groups of samples. An example of their findings is presented in Figure 4. In addition to excellent staining and preservation of morphological detail, many immunohistological stains performed equally well in the RNAlater preserved samples, suggesting preservation in RNAlater caused no damage to cellular epitopes.

Figure 4. Histology of RNAlater Preserved Tissue. RNAlater preserved samples are suitable for histology and provide excellent morphological detail. Sections made from RNAlater preserved material were indistinguishable from slides made from untreated samples when examined for standard histological criteria. Panel A. H&E stained, frozen section of human skin preserved for one week in RNAlater prior to processing. Panel B. Stained as above but formalin-fixed, paraffin-embedded section of human skin preserved for one week in RNAlater prior to processing.

How practical is RNAlater?

This revolutionary and inexpensive product preserves the integrity of your precious RNA and saves you the time and trouble of grinding frozen tissue in liquid nitrogen. RNAlater is economical and can be stored at room temperature.