2013 May 16; 497(7449): 332–337. doi:10.1038/nature12107 | Kwanghun Chung, Jenelle Wallace, Sung-Yon Kim, Sandhiya Kalyanasundaram, Aaron S. Andelman, Thomas J. Davidson, Julie J. Mirzabekov, Kelly A. Zalocusky, Joanna Mattis, Aleksandra K. Denisin, Sally Pak, Hannah Bernstein, Charu Ramakrishnan, Logan Grosenick, Viviana Gradinaru, Karl Deisseroth
The article presents a groundbreaking method called CLARITY, which transforms intact biological tissues into a transparent, optically accessible hybrid of hydrogel and tissue. This technique allows for high-resolution imaging and molecular analysis of entire biological systems without the need for sectioning. The method involves crosslinking tissue with hydrogel monomers and formaldehyde, followed by the removal of lipids using an electrophoretic tissue clearing (ETC) process. This results in a stable, transparent tissue that retains its structural and molecular integrity, enabling detailed imaging of cellular structures, protein complexes, and neurotransmitters in intact tissues.
The study demonstrates the application of CLARITY on mouse brains, revealing long-range projections, local circuit wiring, and subcellular structures. It also enables in situ hybridization, immunohistochemistry, and multiple rounds of staining without tissue sectioning. The method is further validated on human tissue samples, showing its potential for clinical applications. CLARITY allows for the visualization of neurons and their projections in post-mortem human brains, providing insights into neurological disorders.
The technique is particularly useful for studying complex biological systems, as it maintains the global perspective needed for understanding system function while enabling detailed molecular analysis. It overcomes the limitations of traditional methods that either require sectioning or are incompatible with molecular phenotyping. CLARITY's ability to preserve molecular information and structural details makes it a powerful tool for both basic research and clinical applications, offering a pathway to explore the structural and molecular underpinnings of physiological function and disease. The method is described in detail, including its application in imaging, molecular phenotyping, and its potential for future research in neuroscience and beyond.The article presents a groundbreaking method called CLARITY, which transforms intact biological tissues into a transparent, optically accessible hybrid of hydrogel and tissue. This technique allows for high-resolution imaging and molecular analysis of entire biological systems without the need for sectioning. The method involves crosslinking tissue with hydrogel monomers and formaldehyde, followed by the removal of lipids using an electrophoretic tissue clearing (ETC) process. This results in a stable, transparent tissue that retains its structural and molecular integrity, enabling detailed imaging of cellular structures, protein complexes, and neurotransmitters in intact tissues.
The study demonstrates the application of CLARITY on mouse brains, revealing long-range projections, local circuit wiring, and subcellular structures. It also enables in situ hybridization, immunohistochemistry, and multiple rounds of staining without tissue sectioning. The method is further validated on human tissue samples, showing its potential for clinical applications. CLARITY allows for the visualization of neurons and their projections in post-mortem human brains, providing insights into neurological disorders.
The technique is particularly useful for studying complex biological systems, as it maintains the global perspective needed for understanding system function while enabling detailed molecular analysis. It overcomes the limitations of traditional methods that either require sectioning or are incompatible with molecular phenotyping. CLARITY's ability to preserve molecular information and structural details makes it a powerful tool for both basic research and clinical applications, offering a pathway to explore the structural and molecular underpinnings of physiological function and disease. The method is described in detail, including its application in imaging, molecular phenotyping, and its potential for future research in neuroscience and beyond.