RNAlater® Tissue Collection: RNA Stabilization Solution is an aqueous tissue storage reagent that protects RNA within intact, unfrozen tissue samples. RNAlater Solution was designed to eliminate the need to immediately process tissue samples or to freeze samples in liquid nitrogen for later processing. This has proved advantageous in situations in which sample deep freezing methods are not convenient and sample numbers are large, e.g., when sampling a large number of patients in a clinical setting. In the studies described below, Drs. Cui and Gardner both use RNAlater Solution to store and stabilize clinical skin biopsy samples, utilizing gene expression analysis via real time RT-PCR and array analysis, respectively.

RNAlater® Solution Preserves Colorectal Biopsy Samples for Real-time PCR Studies

Monitoring changes in mRNA expression levels aids in understanding the pathogenesis of inflammatory bowel disease. While real-time PCR has become a convenient method for measuring mRNA expression, it requires high quality RNA to get consistent and reproducible results. Dr. Cui and colleagues (University of Tromse, Norway and University Hospital of North Norway) were optimizing their laboratory procedures for endoscopic biopsy sampling and technique to preserve RNA integrity during transport for subsequent use in real-time PCR experiments [1]. Samples from five patients were preserved in RNAlater® Solution at room temperature, and RNA integrity was compared in samples that had been stored for one hour vs. eight days.

The integrity of RNA from samples stored for eight days (RIN=8.50 ± 0.42) in RNAlater Solution was comparable to that from samples stored for just one hour (RIN = 9.04 ± 0.27) indicating that RNA remained undegraded during transport in RNAlater Solution even after eight days at room temperature. The stability afforded by RNAlater Solution improved the clinical use of real-time PCR for quantification of TNF-α gene expression in these colorectal biopsies.

RNAlater® Solution Stabilizes and Preserves Scleroderma Skin Samples for Gene Profiling with Affymetrix Arrays

When collecting numerous samples for gene expression profiling studies, it is critical to control for variation introduced by different sample collection methods and subsequent RNA preservation. Dr. Gardner and colleagues (Cambridge Massachusetts, Medical University of South Carolina, Warsaw Medical Academy, Poland, and University of Texas Medical School at Houston) addressed whether biopsy specimens obtained from systemic sclerosis lesions exhibited a gene profile that was distinct from fibroblast cultures [2]. In his study, Dr. Gardner controlled for the variable sources of RNA collection and preservation conditions by storing the biopsy samples and fibroblast cultures in RNAlater Solution prior to RNA isolation. The purified RNA from the scleroderma biopsies, control skin biopsies, and four control explanted fibroblasts from nine patients and nine controls were subsequently hybridized to Affymetrix® arrays.

The results from RNAlater Solution-treated tissue indicated that scleroderma has a distinct gene profile that is incompletely reflected in profiles from fibroblast cultures. Results confirmed a constant yet different expression pattern across the controls, indicating that RNAlater Solution can stabilize RNA for subsequent gene profiling. RNAlater Solution provides flexibility for sample collection and storage, and helps ensure that high quality RNA is preserved in samples.

References

  1. Cui G, Olsen T, Christiansen I, Vonen B, Florholmen J and Goll R (2006) Improvement of real-time polymerase chain reaction for quantifying TNF-α mRNA expression in inflamed colorectal mucosa: An approach to optimize procedures for clinical use, Scand J Clin Lab Invest 66:249–260.

  2. Gardner H, Shearstone J, Bandaru R, Crowell T, Lynes M, Trojanowska M, Pannu J, Smith E, Jablonska S, Blaszczyk M, Tan F, and Mayes M (2006) Gene profiling of scleroderma skin reveals robust signatures of disease that are imperfectly reflected in the transcript profiles of explanted fibroblasts. Arthritis & Rheumatism 54:1961–1973.