A high-power field (HPF), when used in relation to
microscopy, references the
field of view
The field of view (FoV) is the extent of the observable world that is seen at any given moment. In the case of optical instruments or sensors it is a solid angle through which a detector is sensitive to electromagnetic radiation.
Human ...
under the maximum magnification power of the objective being used. Often, this represents a 400-fold
magnification when referenced in scientific papers.
Area
Area per high-power field for some microscope types:
*Olympus BX50, BX40 or BH2 or AO: 0.096 mm
2[
*AO with 10x eyepiece: 0.12 mm2][
*Olympus with 10x eyepiece: 0.16 mm2][
*Nikon Eclipse E400 with 10x eyepiece and 40x objective: 0.25mm2
*Leitz Ortholux: 0.27 mm2][
*Leitz Diaplan: 0.31 mm2][
]
Examples of usage
The area provides a reference unit, for example in reference ranges for urine tests
Reference ranges for urine tests are described below:
See also
* Reference range
* Reference ranges for blood tests
References
{{Urine tests
Nephrology
...
.[Normal Reference Range Table]
from the University of Texas Southwestern Medical Center
The University of Texas Southwestern Medical Center (UT Southwestern or UTSW) is a public academic health science center in Dallas, Texas. With approximately 18,800 employees, more than 2,900 full-time faculty, and nearly 4 million outpatient vi ...
. Used in interactive case study companion to pathologic basis of disease.
Used for grading of soft tissue tumors: Grading, usually on a scale of I to III, is based
on the degree of differentiation, the average number of
mitoses
In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is maintai ...
per high-power field, cellularity, pleomorphism
Pleomorphism may refer to:
* Pleomorphism (cytology), variability in the size and shape of cells and/or their nuclei
* Pleomorphism (microbiology), the ability of some bacteria to alter their shape or size in response to environmental conditions
...
,
and an estimate of the extent of necrosis (presumably a
reflection of rate of growth). Mitotic counts and necrosis
are the most important predictors.[Robbins Basic Pathology, 9e pg 792]
The following grading is part of classification of breast cancer
Breast cancer classification divides breast cancer into categories according to different schemes criteria and serving a different purpose. The major categories are the histopathological type, the grade of the tumor, the stage of the tumor, and ...
:
References
Microscopy
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