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

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 immunoreactivi ty 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 p ractice, 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.
Source: Histochemistry and Cell Biology - Category: Biomedical Science Source Type: research