U4 LEC: FIXATION Flashcards
First step in histotechnology
Fixation
Fixation is a chemical process by which biological tissues are preserved from?
decay
This is a process of preserving cells and tissue constituents in a?
life-like manner
T/F: Fixation is done to preserve the original state of tissue before the blood supply was cut off.
TRUE
Common specimens in the laboratory
Human tissue from Biopsy or Autopsy
Dysfunctional ______ can also be submitted
organs
Objectives of Fixation
- preserve morphological and chemical integrity of cell
- harden and preserve tissue
- prevent or arrest degenerative processes
Fixation prevents what processes?
- degeneration
- decomposition
- putrefaction
- autolysis
What must be seen in the tissue?
nucleus, cytoplasm, membrane (epithelial cells)
This chemical is found in certain organs.
Hyaluronic Acid
In immunohistochemistry, the membrane is preserved for the diagnosis of?
cancers
This process produces decaying tissue.
Autolysis
Physical Methods of Fixation
- Heat fixation
- Microwave fixation
- Cryo preservation
T/F: Fixation is a largely chemical process.
TRUE
Chemical Methods of Fixation
- Immersion Fixation and Perfusion Fixation
- Coagulant fixatives
- Nom-coagulant cross linking fixative
Temperature of fixative for Rush Frozen Section
freezing temperature (low temperature)
Most commonly used in Fixation
- Formalin
- Formolsaline
Fixation involved with agitating the sample in fixative
Perfusion Fixation
This clotting factor will stabilize the clot formation.
Factor 13
Factor 13 will form what in order to stabilize clot?
cross linking (hardens tissue)
This refers to non coagulant cross linking fixatives in which a chemical constituent is taken into the cell, forming molecular complexes and stabilizing proteins.
Additive Fixation / Non-Coagulant Fixatives
