Simple ambient preservation of human tissues for RNA expression array analysis

We used quantitative RNA expression profiling on the Affymetrix U133 human expression array to validate quantitative expression results obtained with the tissue preservative RNALater against snap frozen and fresh tissues as a means of routine tissue collection and temporary storage. By using split samples from a homogenous tissue (uterine myometrium), and including duplicates within each processing group compared, we were able to undertake a formal ANOVA analysis comparing the magnitude of result variation contributed by sample source (different patients), processing protocol (fresh vs. frozen vs. 24 or 72 hours RNALater), and random background (duplicates). The dataset was randomly permuted to define a baseline pattern of test statistic values against which the observed results could be interpreted. Ambient storage of tissues for 24 or 72 hours in RNALater did not contribute any systematic shift in quantitative RNA expression results relative to the alternatives of fresh or frozen tissue. Keywords: parallel sample