Tissue clearing and labelling with Megasound

Chemical tissue clearing encompasses techniques designed to render biological tissues optically transparent, in other words, to make them see -through. Immersing a specimen such as brain or muscle tissue into a special solution with an appropriately matched refractive index modifies its optical properties, allowing light to pass through. This approach enables the acquisition of high - resolution three -dimensional images of the anatomical fine structure of intact organs. It provides unprecedented access to complex biological architectures, such as entire neuronal or vascular networks, in their native state, eliminating the need for sectioning. Avoiding sectioning is critical, as physical slicing can damage delicate structures and introduce artifacts that may confound interpretation. A significant limitation of current tissue clearing protocols lies in the final diffusion -based penetration of the clearing solution, which proceeds slowly and often incompletely. The present study aimed to address this bottleneck. We evaluated whether high - frequency acoustic stimulation (ultrasonic waves) could enhance the speed and efficacy of clearing solution infiltration into biological tissues. Furthermore, we also investigated whether the application of selected wavelengths laser light could provide an additional improvement in clearing efficiency. Our experimental findings were highly promising. Ultrasound treatment not only produced the anticipated moderate acceleration of the clearing process, but, critically, also yielded a substantial increase in the final transparency of the tissue. This enhanced transparency represents a meaningful advance, as it enables sharper, more detailed 3D reconstructions and strengthens our ability to investigate the intricate architecture of biological systems.