What Tissue Clearing Is
Tissue clearing renders biological tissue optically transparent by matching refractive indices, allowing light to penetrate thick samples. Combined with light-sheet microscopy, it enables imaging of intact brain volumes in 3D.
Why It Matters
Clearing bypasses the need to reconstruct 3D structure from many thin sections, giving a holistic view of connectivity, vasculature and cell distribution across large volumes.
Common Clearing Methods
- Solvent-based (e.g. organic solvents): strong clearing, good for large samples.
- Aqueous/hydrogel-based (e.g. CLARITY): preserves fluorescence well.
- Simple immersion: gentle, low-cost, suitable for thinner samples.
Role of Sectioning in Clearing Workflows
Even in clearing workflows, precise sectioning is often needed to trim blocks to a manageable size or to collect reference sections for validation. High-quality vibratome sectioning keeps the block face clean and the sample intact.
Practical Considerations
Choose a clearing method matched to your label and tissue, be aware of sample shrinkage, and image quickly before signal fades.