Definitions of Histology related terms
On this page we aim to explain a few common terms used on-the-job.
Technical staff, qualified in appropriate sciences, who work in pathology laboratories to
prepare materials for subsequent diagnostic reporting by pathologists.
Histology samples are stored permanently in blocks of paraffin wax. This keeps the
sample stable and also holds it solidly when thin sections must be cut from it.
A colloquial term used, in British clinical histopathology laboratories, to describe
a session of dissection. This is usually performed by a pathologist but may also be
done by a senior technician.
More correctly known as sectioning or microtomy, this is the process of slicing very
thin sections of material from the surface of a histology block. The sections are
typically between 3 and 5 µm in thickness.
The study of cells. This especially applies to cells not held in a sctructural matrix such
as plant or animal tissues - therefore, fluids containing cells.
The study of diseased cells, usually held in fluids or exfoliated from surfaces.
The best known example of this is the screening of women, for cervical cancer,
by use of cervical smears.
An acidic dye which binds with basic tissue components (membranes, cytoplasm etc.). Widely
used in "H&E" staining, the most common morphological stain in histology and cytology. In
these preparations, eosin stains all cellular components, except the nuclei, in shades of red
and pink.
A basic dye which binds with acidic tissue components (nucleic acids such as DNA). Widely
used in "H&E" staining, the most common morphological stain in histology and cytology. In
these preparations, haematoxylin stains cell nuclei in shades of blue and purple.
Histology is the study of cellular tissue architecture using microscopy. This includes
work on both plant and animal species.
Adding the fragment 'patho' into histology gives us the study of diseases in tissues. In
terms of clinical laboratories, this is the more correct term to use since we aim to locate
and classify diseases of the tissues. In practice, this most commonly means cancers.
Known as 'Immuno' for short, this is the process of building complexes on molecular or proteinaceous
targets within cells. These complexes "amplify" the appearance of the target molecule. This means
the complex is large enough to be stained and viewed down the microscope. This method allows easier
classification of cancers - especially those that look similar morphologically.
A device used for viewing objects too small to be resolved by the human eye. In this case,
individual cells in pathological preparations, presented on glass slides.
A machine used for cutting very thin slices of tissue from plant or animal specimens. It can
be thought of as a much more precise and delicate version of a butcher's meat slicing machine.
A medical doctor who, after qualifying in general medicine, has taken a course of
studies in order to specialise in the diagnosis of diseases through the study of pathological
preparations. A histopathologist may also conduct post-mortem examinations (autopsy).
Glass microscope slides which are used to hold permanent or temporary pathology preparations
for viewing down a microscope.