What stains mucin?
There are a variety of stains for mucin: Colloidal iron (“AMP”) – Iron particles are stabilized in ammonia and glycerin and are attracted to acid mucopolysaccharides. It requires formalin fixation. Phospholipids and free nucleic acids may also stain.
Is mucin a Basophilic?
Conspicuous dermal mucin can often be seen on H&E stains alone as basophilic gray/blue strands of wispy material in between and adherent to collagen bundles , as in this case of SCLE.
Why might we need to use Alcian blue to stain mucins?
Alcian Blue is a basic dye containing copper, which gives it the blue color. The stain molecules carry a positive charge and are attracted to the negative mucins. Adjusting the PH of the Alcian Blue solution allows the demonstration of sub-types of acid mucins.
What is the difference between mucin and mucus?
Mucus is a “slimy” material that coats many epithelial surfaces and is secreted into fluids such as saliva. Mucins are a family of large, heavily glycosylated proteins. …
How do you make Mucicarmine stain?
Method
- Bring sections to distilled water.
- Stain nuclei with alum haematoxylin 2 mins.
- Wash in running tap water.
- Differentiate in acid alcohol.
- Rinse in tap water.
- Blue in Scott’s tap water substitute.
- Wash in running tap water.
- Stain with mucicarmine solution 20 mins.
What color is Mucicarmine mucins?
Alcian blue
The typical mucin special stains contain cationic (positively charged) dye molecules in solution at a specific pH. This is true in the case of mucicarmine, Alcian blue as well as the older metachromatic techniques that utilized such dyes as azure A or toluidine blue.
What is mucin made of?
Mucins are highly O-glycosylated proteins that consist of approximately 50–80% carbohydrate by weight and are produced in epithelial cells and mucin-secreting goblet cells.
What is gastric mucin?
Gastric mucin is a large glycoprotein which is thought to play a major role in the protection of the gastrointestinal tract from acid, proteases, pathogenic microorganisms, and mechanical trauma.
What is the composition of mucin?
What gland produces mucin?
Mucin Producing Tissues of the Ocular Surface. Acinar cells of the lacrimal gland, epithelial cells of the cornea and conjunctiva, and goblet cells of the conjunctiva synthesize and secrete mucins onto the ocular surface.
What is Mucicarmine stain used primarily for?
Mucicarmine stain 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.
How is Mucicarmine stain used in immunohistochemistry?
A mucicarmine stain can be used to highlight intracytoplasmic mucin droplets, while it also highlights extracellular mucinous material. Several immunohistochemistry studies can be positive in MEC, with p63 highlighting many of the neoplastic cells in this clear cell variant.
How are aluminum cations used to stain mucins?
The aluminum cations confer an overall positive charge to the large carmine complex. Although the exact mechanism (s) by which this complex selectively stains mucins is unknown, evidence suggests that it is by electrostatic attraction to the anionic groups of acid mucins.
What kind of dye is used In mucicarmine stain?
The active dye molecule found in the mucicarmine stain is a chelate complex formed between cationic aluminum ions and carminic acid. Carminic acid is a natural dye molecule that is isolated from the dried bodies of female Coccus cacti insects. The aluminum cations confer an overall positive charge to the large carmine complex.
Can a neutral mucin be stained with alcian blue?
The Alcian blue at a pH of 2.5 will stain all acid mucins deep blue but will not color the neutral mucins. The subsequent application of the PAS technique will stain the neutral mucins bright magenta. Tissues or cells that contain both neutral and acidic mucins may demonstrate a dark blue or purple coloration (Figure 4).