Phosphotungstic acid-haematoxylin stain

Staining technique used in histology

Phosphotungstic acid-haematoxylin stain (PTAH) is a histological staining method used to highlight specific tissue components, particularly in muscle and connective tissues. This technique is valuable in the field of pathology for identifying certain pathological changes in tissues.

Principle

PTAH staining is based on the use of phosphotungstic acid and haematoxylin, which together form a complex that binds to specific tissue elements. The stain is particularly effective in demonstrating muscle striations, fibrin, and glial fibers. The phosphotungstic acid acts as a mordant, enhancing the binding of haematoxylin to the tissue components.

Procedure

The PTAH staining procedure involves several steps:

1. Fixation: Tissue samples are typically fixed in a formalin-based solution to preserve cellular structures.
2. Deparaffinization and Hydration: Paraffin-embedded tissue sections are deparaffinized and hydrated through a series of alcohols to water.
3. Staining: The sections are then stained with the PTAH solution, which contains phosphotungstic acid and haematoxylin.
4. Differentiation: The sections may be differentiated in a solution to remove excess stain, enhancing contrast.
5. Dehydration and Mounting: Finally, the sections are dehydrated, cleared, and mounted for microscopic examination.

Applications

PTAH stain is particularly useful in the following applications:

• Muscle Pathology: It is used to highlight muscle striations and can help in diagnosing conditions such as muscular dystrophy.
• Neuropathology: PTAH can demonstrate glial fibers, aiding in the study of gliosis and other neurological conditions.
• Cardiac Pathology: It is used to identify contraction band necrosis in myocardial tissue, which is indicative of acute myocardial infarction.

Acute myocardial infarction with contraction band necrosis

Advantages and Limitations

Advantages

• Specificity: PTAH is highly specific for certain tissue elements, making it a valuable tool in diagnostic pathology.
• Contrast: The stain provides excellent contrast, allowing for clear visualization of structures such as muscle fibers and fibrin.

Limitations

• Complexity: The staining procedure is more complex and time-consuming compared to other staining methods.
• Reagent Stability: The reagents used in PTAH staining can be unstable and require careful preparation and handling.

Related pages

• Histology
• Staining (biology)
• Haematoxylin
• Pathology