Histopathology and Cytopathology Department SOPs

The Alcian blue stain is a histological staining technique used to detect and differentiate acidic mucins and other acid glycosaminoglycans (GAGs) in tissue sections. It is commonly employed in various fields such as histopathology, embryology, and connective tissue research to assess the presence and distribution of acidic mucins in tissues. Principle: The principle of the Alcian blue stain is based on the selective affinity of Alcian blue dye for acidic mucopolysaccharides and GAGs. The staining involves the following steps: Tissue pretreatment: Tissue sections are usually deparaffinized and rehydrated to remove the paraffin and restore the tissue's hydration. Alcian blue staining: The tissue sections are immersed in an Alcian blue solution, typically at a pH of 1.0 or 2.5. The Alcian blue dye binds to the acidic mucins and GAGs present in the tissue. Counterstaining: In some protocols, a nuclear counterstain, such as nuclear fast red or hematoxylin, is used to visualize the cell

Masson's trichrome stain is a histological staining technique used to differentiate and visualize different tissue components in histology slides. It is particularly useful for highlighting collagen fibers, muscle fibers, and other connective tissues. The stain involves a series of color changes that allow for the identification and differentiation of various tissue components. Principle: The principle of Masson's trichrome stain is based on the differential affinity of tissue components for specific dyes. The stain involves three main steps: Nuclear staining: The tissue section is stained with a nuclear stain, usually Harris hematoxylin. This step imparts a blue color to the cell nuclei. Cytoplasm and muscle fiber staining: The tissue section is treated with a mixture of acidic dyes, such as acid fuchsin and ponceau acid fuchsin. This step stains the cytoplasm, muscle fibers, and keratin in red or pink. Collagen staining: The tissue section is immersed in aniline blue or light

Introduction: The Periodic Acid-Schiff with Diastase (PASD) stain is a commonly used histochemical staining technique in pathology that enables the detection of glycogen, basement membranes, and fungal organisms in tissue samples. PASD stain is widely used for the diagnosis of a variety of conditions, including glycogen storage diseases, basement membrane disorders, and fungal infections. In this stain, the periodic acid oxidizes the polysaccharides, while the Schiff's reagent binds to the oxidized sugars, producing a magenta color under the microscope. Requirements: The PASD stain requires the following reagents and equipment: Periodic acid Schiff's reagent Diastase enzyme Hydrochloric acid Harris hematoxylin Deionized water Alcohol and xylene for dehydration and mounting Glass slides and coverslips Tissue samples Principle: The PASD stain works on the principle of oxidative cleavage of the polysaccharides by periodic acid, followed by the binding of the oxidized sugars to Sch

Introduction : The Papanicolaou stain, commonly known as the Pap stain, is a widely used cytological staining technique that is used to detect and diagnose abnormal cells in cervical and other gynecological specimens. The Pap stain is a critical tool in screening for cervical cancer and other gynecological diseases. Requirements: Cervical or other gynecological specimens Fixative (e.g., ethanol, methanol) Hematoxylin solution 1% acid alcohol 0.1% Ammonia  Eosin Azure 50 ( EA 50) Orange G 6 (OG 6) Phosphotungstic acid solution Different grades of alcohol (70%, 95%, and absolute) Xylene Microscope slides Coverslips Principle: The Pap stain is a multicolor staining technique that differentiates and stains cellular components in gynecological specimens. The stain involves four main steps: nuclear staining with hematoxylin, cytoplasmic staining with orange G, nuclear counterstaining with phosphotungstic acid, and counterstaining with eosin. The resulting coloration allows the identification

P eriodic acid-Schiff (PAS) stain Introduction: The periodic acid-Schiff (PAS) stain is a histological method for identifying aldehyde-containing macromolecules such as carbohydrates, glycoproteins, and other compounds in tissue samples. It's frequently used to spot fungi, glycogen, and basement membranes in tissues. Diagnosing disorders such as kidney ailments, fungal infections, and diseases affecting glycogen storage requires the use of PAS staining. Requirements: To perform PAS staining, you will need the following materials: Paraffin-embedded tissue sections Periodic acid solution Schiff reagent Hematoxylin solution Different grades of alcohol (70%, 95%, and absolute) Xylene Microscope slides Coverslips Principle: In PAS staining, the tissue's carbohydrates are broken down by periodic acid into aldehydes, which combine with the Schiff reagent to give the sample a magenta hue. Fuchsin, a component of the Schiff reagent, combines with the aldehydes

Hematoxylin and Eosin (H&E) staining  Introduction: In histology and pathology, hematoxylin and eosin (H&E) staining is the staining method most frequently employed. It is a frequently used method to view the cellular makeup of tissues and to make medical diagnoses. Hematoxylin stains the nuclei of cells blue-purple, while eosin stains the cytoplasm and extracellular matrix pink. Requirements: Paraffin-embedded tissue sections Hematoxylin solution Eosin solution (1%) Different grades of alcohol (70%, 95%, and absolute) Xylene Acid  alcohol  Ammonia water   Microscope slides Coverslips DPX/Canada balsam Principle: First  the  tissue  is  cleared  of  all  wax   and  then  rehydrated  to  facilitate  the  entry  of   dyes.  The nuclei, ribosomes, and some cytoplasmic granules in the tissue are acidic and are stained by the basic pigment hematoxylin. Eosin is an acidic dye that stains the tissue's fundamental elements, including collagen and cytoplasm