The three-dimensional nature of biological specimens poses a challenge to whole organ imaging, due to the obscuring effects of light scatter. Innovative tissue-clearing techniques, combined with advances in imaging of cleared tissue, have increasingly been under investigation as substitutes for histological methods. Researchers from Ludwig Maximilian University have established a novel tissue-clearing and whole-body imaging technique, named “ultimate DISCO” (uDISCO).
Tissue clearing and shrinkage (up to 65%) were achieved by exposure to a solvent, which eliminated water and fat content over the course of several days. Using this technique, the researchers processed rodent bodies to the point of organ and whole-body transparency, thereby facilitating optical imaging of the entire brain and full length of the spinal cord, which were specifically labelled with a green fluorescent protein. The result was 3-dimensional visualization of the entire central nervous system with unprecedented clarity.
The technique may be extremely useful for tracking stem cell transplants, elucidating complex neuronal networks, analyzing tumor metastasis at the cellular level, and studying various central nervous system disorders, including brain and spinal cord injury, dementia, stroke, and epilepsy. The researchers’ goal is to process and visualize a whole human brain using this technique in the near future. Overall, the potential applications of this technique in the field of biomedicine are far-reaching, given that a wide variety of cell types can be labeled with specific fluorescent markers or antibodies.
Take a look at this video showing off 3D imaging of the nervous system of a nearly transparent mouse:
Study in Nature Methods: Shrinkage-mediated imaging of entire organs and organisms using uDISCO