Coping with formalin banning in pathology: under vacuum long-term tissue storage with no added formalin

Luca Mastracci, Alessandro Gambella, Alberto Bragoni, Simona Pigozzi, Lorenza Pastorino, Irene Vanni, Ilaria Tosi, Michela Campora, Roberto Fiocca, Federica Grillo

Research output: Contribution to journalArticlepeer-review


Formalin is toxic and has recently been classified as carcinogenic leading to a proposed European formalin ban. But, the pathology use of formalin has however been completely overlooked, and this is proving to be a relevant issue, as no alternative, reliable, tissue fixative is available. Various systems have been proposed to reduce formalin use and exposure; long-term storage and disposal of formalin is also a problem. With this in mind, under vacuum sealing (UVS) systems have been proposed for transportation/storage, however, for how long tissue retains its characteristics (morphological and molecular) is unknown. This study aims to compare histology specimens stored by formalin immersion (FI) and specimens stored after fixation with UVS technique with no additional formalin, at different time periods. Twenty tissue samples (10FI; 10UVS) were stored for different time periods (15 days, 1–2–3–6–12 months) for a total of 120 samples, compared with regard to their morphology, histochemistry, immunoreactivity (24 specific antibodies) and DNA status. All samples showed well-preserved morphology and overlapping staining quality. A significant reduction in immunoreactivity was however identified in the various time periods, particularly for heat pre-treated nuclear antigens, and this commenced earlier (1 month) for FI. UVS storage showed higher DNA content than FI but slightly poorer DNA integrity. These results add important knowledge to the use of UVS in daily practice, as long-term storage of pre-fixed tissue in UVS is not detrimental to the quality of tissue while having the boon of using very little formalin with less operator exposure and lower disposal costs.

Original languageEnglish
Pages (from-to)501-511
Number of pages11
JournalHistochemistry and Cell Biology
Issue number6
Publication statusPublished - Jun 1 2019


  • Formalin ban
  • Pathology
  • Safety
  • Vacuum storage

ASJC Scopus subject areas

  • Histology
  • Molecular Biology
  • Medical Laboratory Technology
  • Cell Biology


Dive into the research topics of 'Coping with formalin banning in pathology: under vacuum long-term tissue storage with no added formalin'. Together they form a unique fingerprint.

Cite this