Stains For Medical Students. Staining is a biochemical technique of adding a class-specific (DNA, proteins, lipids, carbohydrates) dye to a substrate to qualify or quantify the presence of a specific compound.
Staining is a biochemical technique of adding a class-specific (DNA, proteins, lipids, carbohydrates) dye to a substrate to qualify or quantify the presence of a specific compound.
Stains and dyes are frequently used in biology and medicine to highlight structures in biological tissues for viewing, often with the aid of different microscopes.
Stains may be used to define and examine bulk tissues (highlighting, for example, muscle fibers or connective tissue), cell populations (classifying different blood cells, for instance), or organelles within individual cells.tissue after processing.
Standard processing of formalin-fixed tissue removes small non-protein molecules, especially lipids.
Clinicians need to know only a little about stains used by pathologists in establishing diagnosis.
The following will come in handy in understanding pathology slides and reports
Stains nuclei, ribosomes & rough ER (DNA & RNA - acidic)
Haematoxylin is a metal chelator & is used with aluminum ions, which link it to fixed phosphate groups.
Haematoxylin also stains calcium salts, and bacteria blue-purple.
Structures that stain with haematolxylin are termed basophilic
Stains most cytoplasm proteins which are mostly basic
Eosin (red) binds to free amino groups and thus stains arginine and lysine pink to red.
Air, water, fat, and carbohydrate end up unstained.
Structures that stain with eosin are termed eosinophilic
Haematoxylin & Eosin (H&E)‘Standard Tissue Stain’Most common technique in animal histology & routine pathologyIn general, nuclei stain blue & cytolplasm stains pink to red
Congo Red is a special dye that fits tightly into beta-pleated proteins of all sorts.
Romanowsky stain are all based on a combination of eosinate (chemically reduced eosin) and methylene blue