HOPE--a novel tool for the pathologist.

The growing demand for the detection of prognostic and diagnostic biomarkers by application of molecular-biological techniques has been slowed down to a large degree by the use of formalin and its influence onto antigenic structures and nucleic acids, although other reasons also exist. With regard to morphology a limitation in the possibilities, compared to frozen sections, takes place. With the introduction of the HOPE (Hepes glutamic acid buffer mediated Organic solvent Protection Effect) -fixation to date both have become possible; substantially enlarged possibilities concerning the detection of DNA, RNA and proteins in combination with excellent morphological results comparable to formalin-fixed tissues. We also highlight some aspects from our lung specific work during the last years. Immunohistochemical markers for differential diagnostics of malignancies in the lungs are discussed; their enhanced detectability using the HOPE-technique is pathbreaking for the future. The same holds true for the substantially enhanced detectability of germs (e.g. mycobacteria) in HOPE-fixed tissues.