This International Standard recommends the handling, documentation, storage and processing of frozen tissue specimens intended for RNA examination during the pre-examination phase before a molecular assay is performed. This International Standard is applicable to any molecular in vitro diagnostic examination performed by medical laboratories and molecular pathology laboratories that evaluate RNA extracted from frozen tissue. It is also intended to be used by laboratory customers, in vitro diagnostics developers and manufacturers, as well as institutions and commercial organisations performing biomedical research, biobanks, and regulatory authorities. RNA profiles in tissues can change drastically before and after collection (due to e.g., gene induction or gene down regulation). RNA species can change differently in different donor s 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. Tissues that have undergone chemical stabilization pre-treatment before freezing are not covered in this document. NOTE International, national or regional regulations or requirements may also apply to specific topics covered in this International Standard.