Overview
Section thickness is one of the most important sectioning parameters because it directly affects what your downstream assay can see. The right thickness depends on the tissue, the label and the imaging method.
Thick Sections (150–400 µm)
Thick sections preserve 3D structure and are used for acute-slice electrophysiology, cleared-tissue imaging and reconstructing dendritic trees. They require gentle cutting, ideally on a vibratome.
Medium Sections (40–100 µm)
Medium sections suit immunostaining, fluorescence and stereology, balancing tissue preservation with antibody penetration and optical clarity.
Thin Sections (4–20 µm)
Thin sections give excellent resolution for routine histology and are typically cut on a cryostat or microtome. They are ideal for cell identification but lose 3D context.
Trade-offs
| Thickness | Advantage | Trade-off |
|---|---|---|
| Thick (150–400 µm) | 3D preservation, live tissue | Staining penetration, optics |
| Medium (40–100 µm) | Balance of both | Partial depth |
| Thin (4–20 µm) | Sharp single-plane detail | Loses 3D context |
Match to the Assay
Start from the end point: define what the assay needs, then choose thickness, and validate with a test series before committing the full sample.