Mold design, fabrication and tensile testing of EMBed-812, a tissue embedding epoxy resin

Abstract

Serial sectioning is a process whereby fixed tissue is embedded in a polymer to preserve structure and is then sliced into very thin sections as small as 25nm. Currently, there is a lack of understanding of this embedding material, preventing accurate and clean slicing at this level of precision. This thesis focuses on performing tensile tests to determine some of the material properties-elastic modulus, ultimate tensile strength, yield strength-of the epoxy resin used to embed fixed brain tissue. These results will be used in cutting models and help guide the development of a next-generation cutting instrument for automated serial sectioning of tissue. Ultimately, this machine will make it possible to section and image large volumes of brain tissue, leading to further understanding of neural activity and mechanisms behind cognition and tissue disease. This understanding will make it possible to develop treatments for currently untreatable neural diseases and disorders. This research involves creating a streamlined tensile testing procedure for the embedding epoxy resin, EMBed-812, as well as the analysis of tensile tests. The elastic modulus, ultimate tensile strength, yield strength, and percent elongation at break of EMBed-812 were found to be 4.24 +/- 0.27 GPa, 44.8 +/- 4.0 MPa, 17.2 +/- 2.6 MPa, and 3.73 +/- 1.27%, respectively. This testing process can be improved and further work is suggested.