A new technology for stabilization of biomolecules in tissues for combined histological and molecular analyses.

For accurate diagnosis, prediction of outcome, and selection of appropriate therapies, the molecular characterization of human diseases requires analysis of a broad spectrum of altered biomolecules, in addition to morphological features, in affected tissues such as tumors. In a high-throughput screening approach, we have developed the PAXgene Tissue System as a novel tissue stabilization technology. Comprehensive characterization of this technology in stabilized and paraffin-embedded human tissues and comparison with snap-frozen tissues revealed excellent preservation of morphology and antigenicity, as well as outstanding integrity of nucleic acids (genomic DNA, miRNA, and mRNA) and phosphoproteins. Importantly, PAXgene-fixed, paraffin-embedded tissues provided RNA quantity and quality not only significantly better than that obtained with neutral buffered formalin, but also similar to that from snap-frozen tissue, which currently represents the gold standard for molecular analyses. The PAXgene tissue stabilization system thus opens new opportunities in a variety of molecular diagnostic and research applications in which the collection of snap-frozen tissue is not feasible for medical, logistic, or ethical reasons. Furthermore, this technology allows performing histopathological analyses together with molecular studies in a single sample, which markedly facilitates direct correlation of morphological disease phenotypes with alterations of nucleic acids and other biomolecules.