Histology Fixatives and Their Actions Quiz

Fixatives in Histopathology

• The fixative of choice for tissue photography is not specified in the text.

Fixative Characteristics

• Mercuric chloride fixative may produce black granular deposits, which require dezenkerization to remove.
• ZENKER'S FLUID fixative is used to preserve nuclear structures and cytoplasmic mitochondria.
• Chromic acid fixative is commonly used for the chrome-osmium demonstration of acetic acid fixative structures.
• Osmium tetroxide is a strong oxidizing reagent.
• Trichloroacetic Acid (TCA) is used as a fixative for tissue preservation.

Fixation Process

• Dezenkerization is the process of removing black granular deposits observed when using mercuric chloride fixatives.
• The primary goal of the fixation process in histopathology is to preserve tissue morphology and prevent autolysis.
• Fixation is considered a critical step in routine histopathology because it allows for the preservation of tissue structure and prevents artifacts.
• The optimal pH range for fixation is not specified in the text.
• The typical osmolality range for fixation solutions is not specified in the text.
• Fixatives typically penetrate tissues at a rate of 1-2 mm per hour.
• The working temperature range for routine histopathology fixation is 4-20°C.
• For TB patients, the fixation temperature should be maintained at 4°C.

Special Considerations

• Fixation of hollow organs like intestines and stomach requires special consideration, as they may be prone to collapse.
• Fixation of hard tissues like nails and bones requires special consideration, as they may be difficult to fix.
• Cytoplasmic fixatives are used to preserve the cytoplasm of cells.
• Formalin becomes a part of the tissue due to its mechanism.
• The classification of fixatives based on composition is that fixatives consisting of two or more fixatives are classified as compound fixatives.
• For determining the presence of mucopolysaccharides in cells or tissues, cetylpyridinium chloride is the appropriate fixative.

Techniques

• Cryofixation is a technique that involves the use of frozen tissue sections for fixation.
• The optimum rapid fixation temperature is -30°C to -40°C.

Test your knowledge on the actions of histology fixatives in preserving tissue by stopping cellular activities, preventing autolysis, and stabilizing proteins. Learn about the importance of fixatives in easier handling, resistance to damage, and bacterial decomposition.