A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and may require a mordant to improve the fastness of the dye on the fiber.
The Papanicolaou test is a method of cervical screening used to detect potentially precancerous and cancerous processes in the cervix or, more rarely, anus. Abnormal findings are often followed up by more sensitive diagnostic procedures and, if warranted, interventions that aim to prevent progression to cervical cancer. The test was independently invented in the 1920s by the Greek physician Georgios Papanikolaou and named after him. A simplified version of the test was introduced by the Canadian obstetrician Anna Marion Hilliard in 1957.
Haematoxylin or hematoxylin, also called natural black 1 or C.I. 75290, is a compound extracted from heartwood of the logwood tree with a chemical formula of C
16H
14O
6. This naturally derived dye has been used as a histologic stain, as an ink and as a dye in the textile and leather industry. As a dye, haematoxylin has been called palo de Campeche, logwood extract, bluewood and blackwood. In histology, haematoxylin staining is commonly followed by counterstaining with eosin. When paired, this staining procedure is known as H&E staining and is one of the most commonly used combinations in histology. In addition to its use in the H&E stain, haematoxylin is also a component of the Papanicolaou stain which is widely used in the study of cytology specimens.
Georgios Nikolaou Papanikolaou was a Greek physician, zoologist and microscopist who was a pioneer in cytopathology and early cancer detection, and inventor of the "Pap smear".
Cytopathology is a branch of pathology that studies and diagnoses diseases on the cellular level. The discipline was founded by George Nicolas Papanicolaou in 1928. Cytopathology is generally used on samples of free cells or tissue fragments, in contrast to histopathology, which studies whole tissues. Cytopathology is frequently, less precisely, called "cytology", which means "the study of cells".
Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Stains and dyes are frequently used in histology, in cytology, and in the medical fields of histopathology, hematology, and cytopathology that focus on the study and diagnoses of diseases at the microscopic level. Stains may be used to define biological tissues, cell populations, or organelles within individual cells.
Malachite green is an organic compound that is used as a dyestuff and controversially as an antimicrobial in aquaculture. Malachite green is traditionally used as a dye for materials such as silk, leather, and paper. Despite its name the dye is not prepared from the mineral malachite; the name just comes from the similarity of color.
Brilliant blue FCF is a synthetic organic compound used primarily as a blue colorant for processed foods, medications, dietary supplements, and cosmetics. It is classified as a triarylmethane dye and is known under various names, such as FD&C Blue No. 1 or acid blue 9. It is denoted by E number E133 and has a color index of 42090. It has the appearance of a blue powder and is soluble in water and glycerol, with a maximum absorption at about 628 nanometers. It is one of the oldest FDA-approved color additives and is generally considered nontoxic and safe.
Trichrome staining is a histological staining method that uses two or more acid dyes in conjunction with a polyacid. Staining differentiates tissues by tinting them in contrasting colours. It increases the contrast of microscopic features in cells and tissues, which makes them easier to see when viewed through a microscope.
Eosin Y, also called C.I. 45380 or C.I. Acid Red 87, is a member of the triarylmethane dyes. It is produced from fluorescein by bromination.
Fast Green FCF, also called Food green 3, FD&C Green No. 3, Green 1724, Solid Green FCF, and C.I. 42053, is a turquoise triarylmethane food dye. Its E number is E143.
Masson's trichrome is a three-colour staining procedure used in histology. 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.
Bismarck brown Y also called C.I. 21000 and C.I. Basic Brown 1, is a diazo dye with the idealized formula [(H2N)2C6H3N2]2C6H4. The dye is a mixture of closely related compounds. It was one of the earliest azo dyes, being described in 1863 by German chemist Carl Alexander von Martius. It is used in histology for staining tissues.
Green S is a green synthetic coal tar triarylmethane dye with the molecular formula C27H25N2O7S2Na.
Papanicolaou stain is a multichromatic (multicolored) cytological staining technique developed by George Papanicolaou in 1942. The Papanicolaou stain is one of the most widely used stains in cytology, where it is used to aid pathologists in making a diagnosis. Although most notable for its use in the detection of cervical cancer in the Pap test or Pap smear, it is also used to stain non-gynecological specimen preparations from a variety of bodily secretions and from small needle biopsies of organs and tissues. Papanicolaou published three formulations of this stain in 1942, 1954, and 1960.
A koilocyte is a squamous epithelial cell that has undergone a number of structural changes, which occur as a result of infection of the cell by human papillomavirus (HPV). Identification of these cells by pathologists can be useful in diagnosing various HPV-associated lesions.
Rose bengal (4,5,6,7-tetrachloro-2',4',5',7'-tetraiodofluorescein) is a stain. Rose bengal belongs to the class of organic compounds called xanthenes. Its sodium salt is commonly used in eye drops to stain damaged conjunctival and corneal cells and thereby identify damage to the eye. The stain is also used in the preparation of Foraminifera for microscopic analysis, allowing the distinction between forms that were alive or dead at the time of collection.
Acid fuchsin or fuchsine acid, (also called Acid Violet 19 and C.I. 42685) is an acidic magenta dye with the chemical formula C20H17N3Na2O9S3. It is a sodium sulfonate derivative of fuchsine. Acid fuchsin has wide use in histology, and is one of the dyes used in Masson's trichrome stain. This method is commonly used to stain cytoplasm and nuclei of tissue sections in the histology laboratory in order to distinguish muscle from collagen. The muscle stains red with the acid fuchsin, and the collagen is stained green or blue with Light Green SF yellowish or methyl blue. It can also be used to identify growing bacteria.
Calcofluor-white or CFW is a fluorescent blue dye used in biology and textiles. It binds to 1-3 beta and 1-4 beta polysaccharides of chitin and cellulose that are present in cell walls on fungi, plants, and algae.
Hashime Murayama (1879–1954) was a Japanese American painter and scientific illustrator. He was best known for his exquisite paintings of birds, insects, fish, mammals, and other wildlife. Employed by the National Geographic Society from 1921 to 1941, his work was featured in The National Geographic Magazine.
