Quality assessment of long-term stored formalin-fixed paraffin embedded tissues for histopathological evaluation.

Histopathological examination of formalin-fixed paraffin-embedded (FFPE) tissues that had been stored for 30 years was conducted, and reconstructivity of the results was verified. These FFPE tissues, which were from all organs of male and female rats, were re-sectioned and histopathologically examined using hematoxylin and eosin (HE) staining. In particular, the stainability and morphology of HE sections and reproducibility of microscopic findings in the liver and kidney demonstrated in the original final reports were evaluated.