Ultra-thin sectioning and grinding of epoxy plastinated tissue.

Abstract

With classical sheet plastination techniques such as E12, the level and thickness of the freeze-cut sections decide on what is visible in the final sheet plastinated sections. However, there are other plastination techniques available where we can look for specific anatomical structures through the thickness of the tissue. These techniques include sectioning and grinding of plastinated tissue blocks or thick slices. The ultra-thin E12 technique, unlike the classic E12 technique, starts with the plastination of a large tissue block. High temperatures (30-60°C) facilitate the vacuum-forced impregnation by decreasing the viscosity of the E12 and increasing the vapour pressure of the intermediary solvent. By sectioning the cured tissue block with a diamond band saw plastinated sections with a thickness of <300μm can be obtained. The thickness of plastinated sections can be further reduced by grinding. Resulting sections of <100µm are suitable for histological staining and microscopic studies. Anatomical structures of interest in thick plastinate slices can be followed by variable manual grinding in a method referred to as Tissue Tracing Technique (TTT). In addition, the tissue thickness can be adapted to the transparency or darkness of tissue types in different regions of the same plastinated section. The aim of this study was to evaluate the advantages of techniques based on sectioning and grinding of plastinated tissue (E12 ultra-thin and TTT) compared to conventional sheet-forming techniques (E12).