UNIVERSITY OF CAPE COAST
COLLEGE OF HEALTH AND ALLIED SCIENCE
DEPARTMENT OF BIOMEDICAL SCIENCES
COURSE TITLE: BMD 202 HISTOLOGY PRACTICALS
INDEX NUMBER: AH/BMS22/0144
QUESTION
LIST 10 OTHER HISTOLOGICAL STAINS THAT ARE USED IN THE
HISTOLOGY LAB TO STAIN TISSUE SECTIONS. THIS ESSAY SHOULD
INCLUDE THE STRUCTURES THEY STAIN.
Histological staining is a technique used in histology and involves using various dyes or
stains to highlight specific structures and differentiate them. There are a huge variety of
stains. Below are a few of them;
Alcian Blue Stain- Alcian blue stain is the name given to polyvalent basic dyes. These dyes
can react with compounds containing anionic groups such as acid mucosubstances and acid
mucins and they stain blue because of the presence of copper in the molecule. Several
methods that use Alcian blue at different pH values are available. A general method uses an
Alcian blue solution at pH 2.5. This Alcian blue solution with numerically low pH value can
stain many acidic mucins and acid mucosubstances. The Alcian blue solutions with even
lower pH value color only acidic sulfated mucosubstances (pH 1.0) or strongly acidic
sulfated mucosubstances (pH 0.4). Alcian blue can be used in combination with PAS, which
can therefore simultaneously demonstrate acidic mucins and mucosubstances as well as
neutral mucins. To increase staining specificity for various acidic mucins or mucosubstances,
preceding digestion methods such as testicular hyaluronidase are also applied. This stain is
used to stain acidic mucus and acetic mucins.
Congo Red Stain- Congo red is a direct diazo dye used for staining amyloid in tissue
sections. It is an organic compound which forms complexes with the misfolded proteins
deposited in amyloidosis. Congo red stain is the gold standard for the demonstration
of amyloid in tissue sections. It is used to evaluate the presence and extent of amyloidosis in
different organs. Common diseases for Congo red stain include primary amyloidosis,
amyloid light chain (AL) seen in plasma cell dyscrasias, amyloid A (AA) associated with
inflammatory conditions. It is also known as amyloid stain. It stains amyloid structure of
protein aggregates.
Mucicarmine Stain- It is intended for the staining of mucin. Mucin is a secretion produced
by a variety of epithelial cells and connective tissue cells. In certain intestinal inflammations
or carcinomas, an excess of mucin is secreted by the epithelial cells. The mucicarmine
staining technique is also useful for determining the site of a primary tumor by visualizing
tumor cells producing mucin in an area not containing mucin-producing cells, which means
that the tumor is not affected. Mucicarmine staining is also useful for staining encapsulated
fungi like cryptococcus. The principle of mucicarmine staining is based on the presence of
aluminum that forms a chelating complex with carmine. This changes the charge of the
carmine molecule to a positive charge which allows it to bind to low density acidic substrates
such as mucins. It stains structures such as mucin, tumor cell and neoplasm.
Periodic Acid-Schiff (PAS)- It is a staining procedure is most commonly used in the
histology laboratory to detect glycogen deposits in the liver when glycogen storage disease is
suspected. Glycogen granules may also be visible in tumors of the bladder, kidney, ovary,
pancreas, and lung. Basement membranes, which are present in various tissues in the body,
may also be visualized through the PAS staining procedure. The PAS is most commonly
used to demonstrate the thickness of glomerular basement membrane when renal disease is
being assessed. The PAS staining procedure is also used to demonstrate hyphae and yeastforms of fungi in tissue samples due to the high carbohydrate content of the organism's cell
walls. Common fungal species that are PAS reactive are Candida albicans, Aspergillus
fumigatus, and Cryptococcus neoformans. Neutral mucins in the gastrointestinal tract and
some epithelial mucins will also give a PAS-positive staining reaction. It stains structures
such as mucus, glycocalyx and basal laminae.
Masson Fontana stain- It is based on the properties of melanins. Melanins are a group of
brown-black precipitates in the exact chemical structure is not known. Melanins bind to
proteins and melanin-protein complexes are localized in the cytoplasm of cells in melanin
granules. Melanin has the ability to reduce ammonia silver nitrate solutions to metallic silver
without the use of external reducing agent. Masson - Fontana stain is far from being specific
for melanin, because it also makes it possible to visualize other substances which have the
same properties of reduction, as the argyrophilic granules and the lipofuschines. Masson
Fontana stain can be used for the differentiation of brown pigments (lipofuschine,
hemosiderin, melanin), for the deposition of pigment due to treatments like Minocycline type
II or for the differential diagnosis of hypomelanosis. It is used to stain for melanin which is
found in the skin and hair.
Stain of reticulin is a staining that stains the reticulinic fibers of the stroma and makes it
possible to specify the architecture of the tumors (as for example the follicular architecture).
It is very useful in cases where the tumor is necrotic. It is a key staining in the study of
lesions affecting the organs whose frame is rich in reticulin such as the liver (fibrosis, in
which this color shows the youngest collagen), the spleen and lympathic ganglia (reticulin
weft constituting the skeleton), bone marrow (myelofibrosis). Reticulin stain is based on
the silver impregnation of reticulin fibers that cannot be detected with hematoxylin and eosin
staining. Indeed, this coloration uses the argyrophilic properties of the reticulin fibers. With
this staining, the reticulin fibers are stained black. It is used to stain parenchymal organs eg.
liver
Nissl Staining- It is a histological technique used to visualize the cell bodies of neurons in
the central nervous system. It involves staining brain or spinal cord tissue with a basic dye,
such as cresyl violet or toluidine blue, which selectively stains the nissl bodies within the
cytoplasm of neurons. Nissl bodies are clusters of rough endoplasmic reticulum and
ribosomes involved in protein synthesis. This staining technique allows researchers to study
the morphology, distribution, and density of neurons in different regions of the brain and the
spinal cord. It is used to stain nucleoli and rough endoplasmic reticulum of neurons.
Sudan Black B stain- It is intended for the visualization of lipids. Black Sudan B is used for
the staining of a wide variety of lipids such as phospholipids, steroles and neutral
triglycerides. Black Sudan B is not lipid specific like other Sudan dyes and can also be used
for chromosome staining, Golgi apparatus and leukocyte granules. The dyes of the Sudan
family form a group of solvent-soluble lipid dyes. They are called lysochromes and in the
structural classification they are diazo dyes. Black Sudan B is used in the study of
hematological pathologies because it is able to stain myeloblasts and not lymphoblasts.
Normal granulocyte harbingers show increased sudanophilia which corresponds
approximately to the number of granules. Promyelocytes contain some sudanophilic granules
and mature neutrophils contain a large number of sudanophilic granules. Eosinophilic
granules are also sudanophilic, especially at the edge. Monocytes may not be colored or may
contain some discrete sudanophilic granules. Macrophages often contain sudanophilic
material. They stain substances such as chromosomes and golgi apparatus.
Van Gieson's trichrome-It is used for the differentiation between collagen and smooth
muscle in tumors and to demonstrate the increase in the amount of collagen in these
pathologies. Van Gieson's trichrome is composed of 3 different dyes: Weigert's hematoxylin
for nuclei, picric acid for cytoplasm and fuschine acid for collagen. When combined
solutions of picric acid and acidic fuchsin are used, small picric acid molecules penetrate
rapidly into all tissues, but are firmly retained only in red blood cells and muscle. Larger
fuchsin molecules displace the picric acid molecules of collagen fibers, which have larger
pores, and allow large molecules to enter. Here are some examples of stains obtained with
Van Gieson's trichrome:
Nuclei: Blue
Collagen: bright red
Cytoplasm, muscle, fibrin and red blood cells: yellow
Giemsa stain- It is a type of stain used in microscopy to visualize and differentiate different
types of cells, particularly blood cells and parasites. It is commonly used to diagnose and study
diseases such as malaria, leukemia, and other blood disorders. The stain works by binding to
the DNA and RNA in cells, causing them to appear blue or purple under a microscope. Giemsa
stain is often used in combination with other stains to provide a more comprehensive view of
cell morphology and structure. It stains structures such as erythrocytes and platelets
REFERENCES:
M. Lai, B. Lü (2012) Extraction Techniques and Applications: Biological/Medical and
Environmental/Forensics. Comprehensive sampling and sample preparation.
M nunez