Optical Fractionator Method
Optical Fractionator Method - Related Videos
07:55
The Optical Fractionator Technique to Estimate Cell Numbers in a Rat Model of Electroconvulsive Therapy
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Cited by 24 •
2017
Here, we present a stereological method, the optical fractionator, used to quantify the formation of new neurons, and their survival, in the rat hippocampus following electroconvulsive stimulation. When correctly implemented, the sensitivity and efficiency of stereological methods ensures accurate estimates with a fixed and predetermined precision.
04:25
Preparation of Subcellular Fractions from Leukemic Cells: A Method to Generate Cellular and Nuclear Fractions from Leukemic Cells
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2023
This video describes the preparation of subcellular fractions from leukemic cells which is a method to generate cellular and nuclear fractions from leukemic cells. The nuclear and cytoplasmic fractions can be used for further downstream analysis.
06:00
Quantifying Newly Generated Neurons in Rat Brain Tissue Using the Optical Fractionator Technique
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2025
Source: Olesen, M. V., et al. The Optical Fractionator Technique to Estimate Cell Numbers in a Rat Model of Electroconvulsive Therapy. J. Vis. Exp. (2017). The video demonstrates the technique for quantifying newly generated neurons in brain tissue. Hippocampal tissue slices containing Bromodeoxyuridine (BrdU)-labeled neurons were stained using immunohistochemistry and subsequently quantified across the tissue thickness using the optical fractionator technique.
08:19
Stereological Estimation of Dopaminergic Neuron Number in the Mouse Substantia Nigra Using the Optical Fractionator and Standard Microscopy Equipment
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Cited by 45 •
2017
This work presents a step-by-step protocol for the unbiased stereological estimation of dopaminergic neuronal cell numbers in the mouse substantia nigra using standard microscopy equipment (i.e., a light microscope, a motorized object table (x, y, z plane), and public domain software for digital image analysis.
10:09
Fractional Distillation
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2023
Source: Laboratory of Dr. Nicholas Leadbeater — University of Connecticut Distillation is perhaps the most common laboratory technique employed by chemists for the purification of organic liquids. Compounds in a mixture with different boiling points separate into individual components when the mixture is carefully distilled. The two main types of distillation are "simple distillation" and "fractional distillation", and both are widely used in organic chemistry laboratories. Simple distillation...
FAQs
An optical disector defines a three-dimensional counting probe within the tissue section. Structures are counted according to specified rules, while guard zones keep section surfaces from contributing boundary-related errors. This combination helps preserve the accuracy of counts when structures extend through the sampled tissue.
Systematic, uniform random sampling gives each part of the tissue an organized opportunity for selection, while sampling fractions connect the counted sample to the larger tissue volume. Counting rules then determine which structures enter the estimate. Together, these features reduce dependence on where individual sections happen to be chosen.
The method avoids requiring assumptions about cell size, shape, or distribution. That matters because disease or treatment may alter cellular organization, making such assumptions unreliable across groups. By basing results on defined counting rules and sampling fractions, it supports more defensible comparisons between healthy and diseased tissue.
A typical workflow begins with systematic, uniform random selection of tissue sections. The investigator applies optical disectors to the sampled material, uses guard zones around section surfaces, and counts structures that meet prescribed rules. Sampling fractions are then used to relate those observations to the tissue volume under study.
In medicine, the Optical Fractionator Method can quantify neuronal loss, tumor cell populations, tissue regeneration, or treatment-related cellular changes. The resulting estimates allow researchers to compare healthy and diseased tissues or evaluate cellular differences associated with an intervention. This is useful when cell number, rather than appearance alone, is the relevant outcome.
A higher or lower estimate can indicate a difference in the number of counted structures between tissue groups, such as healthy and diseased samples or samples assessed for treatment-related changes. Interpretation is strongest when the same sampling fractions, optical disector rules, and guard-zone practice are applied consistently across comparisons.