Realizing BRAVE-EM for Nanoscale Multicolor Imaging in Biology: Biological Real-space Absorption Visualization by photoEmission Electron Microscopy

Project Summary/Abstract Imaging cells and tissue labeled with fluorescent molecules and proteins is critical in biological research, enabling visualization of the locations of specific proteins, receptors, or genotypes within cells and tissue. However, our current imaging modalities are not capable of simultaneous functional imaging of molecules/proteins and structural imaging of cellular and subcellular features in whole tissues, limiting both our fundamental biomedical understanding of diseases and strategies for treatment. Leveraging recent advances in the development of photoemission electron microscopy for high-resolution imaging of biological tissue for volume electron microscopy, the proposed research program seeks to develop BRAVE-EM, Biological Real-space Absorption Visualization by photoemission - Electron Microscopy, to combine the wavelength specificity of optical light microscopy with the spatial resolution and volume imaging of electron microscopy. Developing BRAVE-EM will enable imaging of fluorescent molecule and protein labels in biological tissues with spatial resolution <20 nm, while remaining compatible with recent advances in the volume electron microscopy infrastructure. Using volume electron microscopy and BRAVE-EM, we will answer questions in cancer biology, such as how heterogeneity in cancer-associated fibroblasts and variations in protein expression in the tumor stroma of pancreatic tissue samples influences cancer metabolism and disease progression.