RNAlater-ICE Frozen Tissue Transition Solution
Quick Freezing Tissues Preserves RNA
Processing Frozen Tissues is Problematic
Process Frozen Tissue Without Jeopardizing RNA Integrity — RNAlater-ICE
Figure 1 shows the quality of RNA isolated from three different frozen mouse tissues that were immediately homogenized or thawed in RNAlater-ICE overnight at -20ºC. Both the stained gel and the resulting Northern blot demonstrate that RNAs isolated from tissues treated with RNAlater-ICE maintain a high degree of integrity. The dramatic preservation of RNA by RNAlater-ICE is also illustrated in Figure 2. Here we compare RNA that was prepared directly by homogenization of frozen tissue, with a sample that was allowed to thaw at room temperature for 5 minutes, and a sample that was frozen, soaked overnight at -20ºC in RNAlater-ICE, and kept at room temperature for 30 minutes before being processed for RNA isolation. The protective effect of RNAlater-ICE is obvious.
Figure 1. Quality of RNA From Samples Treated With RNAlater-ICE. Total RNA was isolated from various frozen mouse tissue samples that were either processed directly from a frozen state or thawed in RNAlater-ICE at -20ºC overnight. (A) shows the ethidium bromide stained RNA in a denaturing agarose gel. (B) shows the results of Northern blot analysis of the same gel hybridized to radiolabeled probes for ß-actin, GAPDH, and cyclophilin. (Note that the specific activity of the cyclophilin probe was lower than that of the other probes.) For each tissue the integrity of both rRNA and mRNAs for the RNAlater ICE treated samples is comparable to that of RNA prepared directly from frozen tissue samples.
Figure 2. RNA Integrity from Frozen Samples Ground, Thawed or Treated with RNAlater-ICE. Total RNA was isolated from mouse liver samples that were processed directly from a frozen state (ground), thawed on a benchtop for 5 min (thawed), or thawed overnight at -20ºC in RNAlater-ICE and then stored at rt for 30 min prior to RNA isolation (treated). (A) shows the ethidium bromide stained RNA in a denaturing agarose gel. (B) shows the results of Northern blot analysis of the same gel hybridized to radiolabeled probes for ß-actin, GAPDH, and cyclophilin. Note that frozen tissue thawed in the absence of RNAlater-ICE yielded degraded RNA while RNA remained intact when tissue was thawed in RNAlater-ICE.