A well-fixed tissue section for IHC is characterized by excellent preservation of cellular and tissue morphology with clearly defined nuclear and cytoplasmic details, and it should retain strong antigenicity for a wide range of targets. Good fixation is a balance: it must rapidly and uniformly penetrate the tissue to halt degradation (autolysis and putrefaction) and preserve structure by forming cross-links, but not over-fix to the point where antigens become irreversibly masked. In a well-fixed section under the microscope after staining, cells appear crisp, nuclei are distinct, and tissue architecture (like glandular structures or layering) is intact. There should be no signs of poor fixation such as smudgy nuclei, vacuolization, or detachment of cells from the stroma (which can occur with delayed fixation). Crucially, when subjected to appropriate antigen retrieval, the tissue should yield strong, specific IHC staining. The fixative of choice for most IHC is 10% neutral buffered formalin, as it provides good morphology and, despite some antigen masking, allows for consistent retrieval in modern labs.

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Zambia

• loveness Phiri – 1084 pts

• Visual Pathway Lesions
• Positive and Negative Symptoms
• Hallucinations and Delusions
• Antipsychotic Medications
• Emergency: Environmental Emergencies