Thick sections may be oriented as the researcher prefers. Instead the intersections of the filaments with a virtual sphere are marked and converted to a length estimate. SPACEBALLS to estimate LENGTH of fibers and vesselsĮstimate length of biological filaments such as axons or blood vessels without facing the herculean task of tracing them all.
Unbiased estimates of regional volume are easy to obtain efficiently using Cavalieri point-counting. 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. 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. NUCLEATORĬAVALIERI POINT-COUNTING to estimate VOLUME of regions 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. 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. 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. OPTICAL FRACTIONATORĮstimate individual cell volum es with the nucleator. Note: avoid counting pieces of cells when you really want to count whole cells. 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. A virtual space called an optical disector is used in thick sections that can be oriented anyway you like.
OPTICAL FRACTIONATOR to estimate NUMBER of cellsĮstimate 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. These probes should always be used in conjunction with systematic random sampling. These stereological probes are appropriate for many fields of basic and applied biological and medical research. The most modern unbiased stereology probes are used to quantify aspects of biological tissue in a reproducible and efficient manner. 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. It produces results that are unbiased, efficient, and more reliable than other ad hoc quantitative analyses. When properly used, stereology plays an important role in validating and rejecting experimental hypotheses in biological research.
What is Stereology?ĭesign-based stereology is a set of methods to ensure rigorous quantitative analysis of the size, shape, and number of objects. This site is dedicated to helping researchers understand the principles of design-based stereology and its advantages over less sophisticated approaches in quantitative histology. The application of stereological methods to biological studies permits researchers to effectively and efficiently gather unbiased, accurate data. The emphasis is on the use of stereology in biological research, though anyone interested in learning concepts of stereology will find something of interest. This site introduces both basic and advanced concepts of Stereology. Email Stereology Information for the Biological Sciences
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