Masson's trichrome is a three-colour

staining Staining is a technique used to enhance contrast in samples, generally at the Microscope, microscopic level. Stains and dyes are frequently used in histology (microscopic study of biological tissue (biology), tissues), in cytology (microscopic ...

procedure used in

histology Histology, also known as microscopic anatomy or microanatomy, is the branch of biology that studies the microscopic anatomy of biological tissue (biology), tissues. Histology is the microscopic counterpart to gross anatomy, which looks at large ...

. The recipes emerged from Claude L. Pierre Masson's (1880–1959) original formulation have different specific applications, but all are suited for distinguishing cells from surrounding

connective tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...

. Most recipes produce red

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. It is the key structural material making up Scale (anatomy), scales, hair, Nail (anatomy), nails, feathers, horn (anatomy), horns, claws, Hoof, hoove ...

and

muscle fiber A muscle cell, also known as a myocyte, is a mature contractile cell in the muscle of an animal. In humans and other vertebrates there are three types: skeletal, smooth, and cardiac (cardiomyocytes). A skeletal muscle cell is long and threadl ...

s, blue or green

collagen Collagen () is the main structural protein in the extracellular matrix of the connective tissues of many animals. It is the most abundant protein in mammals, making up 25% to 35% of protein content. Amino acids are bound together to form a trip ...

and

bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

, light red or pink

cytoplasm The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...

, and dark brown to black

cell nuclei The cell nucleus (; : nuclei) is a membrane-bound organelle found in eukaryotic cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoc ...

. The trichrome is applied by immersion of the fixated sample into Weigert's iron hematoxylin, and then three different solutions, labeled A, B, and C: * Weigert's

hematoxylin Haematoxylin American and British English spelling differences#ae and oe, or hematoxylin (), also called natural black 1 or Colour Index International, C.I. 75290, is a chemical compound, compound extracted from wood#Heartwood and sapwood, heart ...

is a sequence of three solutions:

ferric chloride Iron(III) chloride describes the inorganic compounds with the formula (H2O)x. Also called ferric chloride, these compounds are some of the most important and commonplace compounds of iron. They are available both in anhydrous and in hydrated f ...

in diluted

hydrochloric acid Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...

in 95%

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

, and

potassium ferricyanide Potassium ferricyanide is the chemical compound with the formula K3 e(CN)6 This bright red salt contains the octahedral molecular geometry, octahedrally coordination compound, coordinated ferricyanide, e(CN)6− ion. It is soluble in wat ...

solution alkalized by

sodium borate Sodium borate is a generic name for any salt (chemistry), salt of sodium with an anion consisting of boron and oxygen, and possibly hydrogen, or any hydrate thereof. It can be seen as a hydrated sodium salt of the appropriate boroxy acid, although t ...

. It is used to stain the nuclei. * Solution A, also called plasma stain, contains acid fuchsin, Xylidine Ponceau,

glacial acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main compone ...

, and

distilled water Distilled water is water that has been purified by boiling it into vapor then condensing it back into liquid in a separate container. Impurities in the original water that do not boil below or near the boiling point of water remain in the origin ...

. Other red acid dyes can be used, e.g. the Biebrich scarlet in Lillie's trichrome. * Solution B contains phosphomolybdic/ phosphotungstic acid in distilled water. * Solution C, also called fibre stain, contains Light Green SF yellowish, or alternatively Fast Green FCF. It is used to stain collagen. If blue is preferred to green, methyl blue or water blue can be substituted. Standard applications: Masson's trichrome staining is widely used to study muscular pathologies (

muscular dystrophy Muscular dystrophies (MD) are a genetically and clinically heterogeneous group of rare neuromuscular diseases that cause progressive weakness and breakdown of skeletal muscles over time. The disorders differ as to which muscles are primarily affe ...

), cardiac pathologies ( infarct), hepatic pathologies (

cirrhosis Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, chronic liver failure or chronic hepatic failure and end-stage liver disease, is a chronic condition of the liver in which the normal functioning tissue, or parenchyma, is replaced ...

) or kidney pathologies (glomerular fibrosis). It can also be used to detect and analyze tumors on hepatic and kidney biopsies.

Variants

A common variant is Lillie's trichrome. It is often erroneously called Masson's trichrome. It differs in the dyes used, their concentrations, and the immersion times. Another common variant is the ''Masson trichrome & Verhoeff stain'', which combines the Masson trichrome stain and Verhoeff's stain. This combination is useful for the examination of

blood vessel Blood vessels are the tubular structures of a circulatory system that transport blood throughout many Animal, animals’ bodies. Blood vessels transport blood cells, nutrients, and oxygen to most of the Tissue (biology), tissues of a Body (bi ...

s; the Verhoeff stain highlights

elastin Elastin is a protein encoded by the ''ELN'' gene in humans and several other animals. Elastin is a key component in the extracellular matrix of gnathostomes (jawed vertebrates). It is highly Elasticity (physics), elastic and present in connective ...

(black) and allows one to easily differentiate small arteries (which typically have at least two elastic laminae) and veins (which have one elastic lamina).

References

External links

Masson's Trichrome Protocol

Trichrome Stain

{{DEFAULTSORT:Masson's Trichrome Stain Staining

Variants

See also

References

External links