HOPE--a new fixing technique enables preservation and extraction of high molecular weight DNA and RNA of > 20 kb from paraffin-embedded tissues. Hepes-Glutamic acid buffer mediated Organic solvent Protection Effect.

The growing number of molecular pathologic tools that are currently available require material with good long term preservation of morphology, nucleic acids, and antigenic structures. However, pathologic investigations of tissues done at a molecular level are often hampered by the fixatives in use. We thus endeavored to design a new fixing system, including subsequent paraffin-embedding and sectioning, that makes complete pathologic analyses possible, with special consideration of immunohistochemistry (IHC), in situ hybridization (ISH), and molecular pathology.