The Most Comprehensive Source of Stereology Information on the Web

Stereology Information for the Biological Sciences

This site introduces both basic and advanced concepts of Stereology. The emphasis is on the use of stereology in biological research, though anyone interested in learning concepts of stereology will find something of interest. The application of stereological methods to biological studies permits researchers to effectively and efficiently gather unbiased, accurate data. This site is dedicated to helping researchers understand the principles of design-based stereology and its advantages over less sophisticated approaches in quantitative histology.

What is Stereology?

Design-based stereology is a set of methods to ensure rigorous quantitative analysis of the size, shape, and number of objects. When properly used, stereology plays an important role in validating and rejecting experimental hypotheses in biological research. It produces results that are unbiased, efficient, and more reliable than other ad hoc quantitative analyses. Unbiased stereology provides an important contribution to the advancement in biological research by improving the consistency and dependability of quantitative analytical results produced in the laboratory and reported in scientific publications.

An Introduction to Stereology Probes

The most modern unbiased stereology probes are used to quantify aspects of biological tissue in a reproducible and efficient manner. These stereological probes are appropriate for many fields of basic and applied biological and medical research. These probes should always be used in conjunction with systematic random sampling.



Estimate the size of cell populations with the optical fractionator in thick tissue sections. In this probe, sub-volumes are sampled and then are extrapolated to arrive at an estimate of the entire cell population. A virtual space called an optical disector is used in thick sections that can be oriented anyway you like. Disector counting rules are followed to avoid overestimating, and an oil objective lens is employed for imaging, since fine z-resolution is needed to find the leading edge of the cell and to have enough focal planes to determine if it is in the disector. Note: avoid counting pieces of cells when you really want to count whole cells.    OPTICAL FRACTIONATOR


NUCLEATOR to estimate VOLUME of cells

Estimate individual cell volumnucleator-2es with the nucleator. A point in the cell is identified, then one to four rays are marked and their mean length is used in the formula for the volume of a sphere, generating an estimate of the cell volume. The volume estimate is number-weighted; the sampling is done with a disector in thick sections so that it is not more likely to sample larger cells than smaller cells. It is important to use a method to select cells without bias by picking them in a manner that does not favor any position of the cell in space; you won’t overestimate by sampling too many larger cross-sections or underestimate by sampling too many smaller cross-sections.    NUCLEATOR




This probe is versatile in that it can be used on thin optical or physical sections that are oriented according to the preference of the researcher. A fraction of the tissue is marked with points over the region(s) of interest, and an extrapolation is carried out to arrive at the estimate. Unbiased estimates of regional volume are easy to obtain efficiently using Cavalieri point-counting.     CAVALIERI/POINT-COUNTING


SPACEBALLS to estimate LENGTH of fibers and vessels


Estimate length of biological filaments such as axons or blood vessels without facing the herculean task of tracing them all. Instead the intersections of the filaments with a virtual sphere are marked and converted to a length estimate. Thick sections may be oriented as the researcher prefers. This probe is implemented along with the fractionator method; a volume-fraction is sampled and extrapolated using the reciprocal of the volume fraction to arrive at the estimate of length.    SPACEBALLS


ISOTROPIC FAKIR to estimate SURFACE of membranes


To estimate surface area, a triplet of line segments that has the property of being isotropic in space is used to probe in thick sections. Intersections of the triplet with the surface are counted and a formula is used to arrive at an estimate of the surface area; the more intersections recorded the greater the surface. Like the other regional probes on this page, thick, preferentially oriented sections are used and the fractionator method works to make an extrapolation based on the fraction of volume that was sampled.     ISOTROPIC FAKIR

more probes including solutions for thin tissue sections


Recommended Readings

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Recent Noteworthy Stereology Publications

Published papers using unbiased stereology; last updated on 06.06.2024.

starindicates that the researchers did a good job reporting stereological parameters. To see what parameters should be reported, click here.

Chronic unpredictable stress induces autophagic death of adult hippocampal neural stem cells

starNorepinephrine Drives Sleep Fragmentation Activation of Asparagine Endopeptidase, Locus Coeruleus Degeneration and Hippocampal Amyloid-β42 Accumulation

Autistic-like behaviour and changes in thalamic cell numbers a rat model of valproic acid-induced autism; A behavioural and stereological study

Discovery of a CCR2-targeting pepducin therapy for chronic pain

Nf1 mutation disrupts activity-dependent oligodendroglial plasticity and motor learning in mice

GDF11 improves hippocampal neurogenesis and cognitive abilities in diabetic mice by reducing neural inflammation

LINE-1 retrotransposons contribute to mouse PV interneuron development

Comparison of different promoters to improve AAV vector-mediated gene therapy for neuronopathic Gaucher disease 

Long-Term Calorie Restriction Reduces Oxidative DNA Damage to Oligodendroglia and Promotes Homeostatic Microglia in the Aging Monkey Brain

JWA binding to NCOA4 alleviates degeneration in dopaminergic neurons through suppression of ferritinophagy in Parkinson’s disease


Suppression of the JAK/STAT Pathway Inhibits Neuroinflammation in the Line 61-PFF Mouse Model of Parkinson’s Disease

Early adversity causes sex-specific deficits in perforant pathway connectivity and contextual memory in adolescent mice

Introduction of a Model for The Modification Of Masticatory Activity To Investigate Induced Neural And Behavioral Alterations In Mice

Early morphological and neurochemical changes of the bed nucleus of stria terminalis (BNST) in gestational protein-restricted male offspring

The isoproterenol-induced myocardial fibrosis: A biochemical and histological investigation

Administration of adipose-derived stem cells extracellular vesicles in a murine model of spinal muscular atrophy: effects of a new potential therapeutic strategy

Spatiotemporal development of the neuronal accumulation of amyloid precursor protein and the amyloid plaque formation in the brain of 3xTg-AD mice

A Comparison of Telencephalon Composition among Chickens, Junglefowl, and Wild Galliforms

Sleep deprivation induces late deleterious effects in a pharmacological model of Parkinsonism


starNuclear parcellation and numbers of orexinergic neurons in five species of larger brained birds

starCeramides as therapeutic targets in bronchopulmonary dysplasia

starTitle: The wake and sleep-modulating neurons of the lateral hypothalamic area demonstrate a differential pattern of degeneration in Alzheimer’s disease.

Spatially conserved pathoprotein profiling in the human suprachiasmatic nucleus in progressive Alzheimer’s disease stages

starNo Evidence Of Sensory Neuropathy In A Traditional Mouse Model Of Idiopathic Parkinson’s Disease

The Mst1/2-BNIP3 axis is required for mitophagy induction and neuronal viability under mitochondrial stress

Subthalamic nucleus deep brain stimulation alleviates oxidative stress via mitophagy in Parkinson’s disease

Escitalopram treatment ameliorates chronic immobilization stress-induced depressive behavior and cognitive deficits by modulating BDNF expression in the hippocampus

Adoptive transfer of mitochondrial antigen-specific CD8+ 1 T-cells in mice causes parkinsonism and 2 compromises the dopamine system.

Pathologic α-Synuclein-NOD2 Interaction and RIPK2 Activation Drives Microglia-Induced Neuroinflammation in Parkinson’s Disease

starPhenotypically concordant distribution of pick bodies in aphasic versus behavioral dementias

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