RNA stabilization of peripheral blood and profiling by bead chip analysis.

Gene expression profiling of peripheral blood is a very attractive approach for the development of new diagnostic markers of blood-borne but also systemic diseases as well as the development of biomarkers for drug development. Since most cellular components of peripheral blood are specialized to quickly respond to exogenous stimuli, sample procurement approaches are required that reduce the overall impact of ex vivo changes in gene expression due to technical issues such as prolonged sample handling or temperature changes during transportation of the blood prior to genome-wide analysis. To address these needs, a whole blood RNA stabilization technology was combined with a bead-based oligonucleotide microarray technology for genome-wide transcriptome analysis. Cells, and thereby also RNA is immediately stabilized after the blood draw by a commercially available device (PAXgene). Total RNA is then extracted from PAXgene-stabilized blood and subjected to microarray analysis. In our hands, the Illumina BeadChip array platform outperformed other microarray platforms. Combining RNA stabilization of peripheral blood with bead-based oligonucleotide microarray technology is not only applicable to small single-center studies with optimized infrastructure but also to large scale multi-center trials that are mandatory for the development of predictive markers for disease and treatment outcome.