This International Standard recommends the handling, documentation, storage and processing of formalin-fixed and paraffin-embedded (FFPE) tissue specimens intended for RNA examination during the pre-examination phase before a molecular assay is performed. This International Standard is applicable to molecular in vitro diagnostic examinations including laboratory developed tests performed by medical laboratories and molecular pathology laboratories. It is also intended to be used by laboratory customers, in vitro diagnostics developers and manufacturers, as well as institutions and commercial organizations performing biomedical research, biobanks, and regulatory authorities. The formalin-fixation and the paraffin-embedding process lead to modifications of the RNA molecules, which can impact the validity and reliability of the examination test results. RNA profiles in tissues can change drastically during collection and change differently in different tissue donors / patients tissues. Therefore, it is essential to take special measures to minimize the described RNA profile changes and modifications within the tissue for subsequent examination. NOTE International, national or regional regulations or requirements may also apply to specific topics covered in this International Standard.