Overview
Stereology provides unbiased, quantitative estimates of cell number, volume and density in tissue, free from the artifacts of two-dimensional counting methods. It is the gold standard for many neuroanatomical counts.
The Problem with Simple Counting
Counting cells on single sections and extrapolating to the whole region introduces bias from cell size, orientation and section thickness. Stereology uses systematic random sampling and 3D probes to correct for these factors.
Key Stereological Principles
- Systematic random sampling: sample evenly and randomly through the region of interest.
- Optical disector: count cells with a 3D probe to avoid double counting.
- Fractionator method: combine sampling with reference volume for unbiased totals.
Sectioning for Stereology
Uniform, randomly oriented sections with known sampling fraction are required. A vibratome gives reproducible thickness ideal for optical-disector counting within thick sections.
Practical Tips
Keep section thickness consistent, account for shrinkage, and blind the analyst to experimental group where possible to avoid expectation bias.