Optical Fractionator

Overview

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The Optical Fractionator probe enables you to sample a 3D region of interest and estimate the total number of particles. The Optical Fractionator is available as a stand-alone probe, however, it is fairly complex to use. Use the Optical Fractionator workflow for step-by-step guidance.

The Optical Fractionator (West, et al., 1991) combines the Optical Disector and the Fractionator for counting. It is unaffected by tissue shrinkage and does not require rigorous definitions of structural boundaries.

Using the Optical Fractionator involves counting objects with optical disectors in a uniform systematic sample that constitutes a known fraction of the volume of the region being analyzed. In practice, this is accomplished by systematically sampling a known fraction of the section thickness, of a known fraction of sectional area, of a known fraction of the sections that contain the region of interest.

Use the Optical Fractionator to perform systematic sampling of populations distributed within a series of serial sections to estimate the population number in a volume. Properly designed systematic sampling yields unbiased estimates of population number.

The theory underlying this sampling methodology also makes it possible to estimate the precision of the population size estimate for a single subject; this estimate of precision is called the Coefficient of Error (CE).

 

Watch this webinar for a practical demonstration of the Optical Fractionator workflow. If you are running Optical Fractionator on a FLUOVIEW system, see SRS Image Series and SRS Image Stack Series for instructions.