What is the effect of 'over-fixation' on a tissue sample?
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Correct answer: It hinders stain penetration and can mask tissue antigens
Prolonged exposure to fixatives like formalin can lead to excessive cross-linking. This 'hardens' the tissue too much and can chemically block the binding sites needed for IHC or special stains.
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More Tissue Preparation questions
- What is the primary objective of the 'fixation' step in tissue preparation?
- Which of the following chemical agents is the most commonly used primary fixative for light microscopy?
- Dehydration of a tissue specimen is typically achieved by passing it through a graded series of:
- What is the specific purpose of the 'clearing' step in the tissue processing sequence?
- During embedding, why must the tissue be carefully oriented in the mold?
- Which instrument is used to cut thin sections (typically 5–10 micrometers) from a paraffin-embedded block?