FRESH TISSUE EXAMINATION Flashcards
A process whereby a selected tissue specimen is immersed in a watch glass containing isotonic salt solution
Teasing or Dissociation
A process whereby small pieces of tissue not more than one mm. in diameter are placed in a microscopic slide and forcibly compressed with another slide or with a cover glass.
Squash Preparation (Crushing)
Process of examining sections or sediments, whereby cellular materials are spread lightly over a slide by means of a wire loop or applicator, or by making an apposition smear with another slide.
Smear Preparation
This technique is especially useful in cytological examinations, particularly for cancer diagnosis.
Smear Preparation
A method of Smear Preparation where a selected portion of the material is transferred to a clean slide and gently spread into a moderately thick film by teasing the mucous strands apart with an applicator stick.
Spreading
A method of Smear Preparation where with an applicator stick or a platinum loop, the material is rapidly and gently applied in a direct or zigzag line throughout the slide, attempting to obtain a relatively uniform distribution of secretion.
Streaking
A method of Smear Preparation that is done by placing a drop of secretion or sediment upon one slide and facing it to another clean slide
Pull-Apart
A special method of smear preparation whereby the surface of a freshly cut piece of tissue is brought into contact and pressed on to the surface of a clean glass slide
Touch Preparation (Impression Smear)
A method of smear preparation that is especially recommended for smear preparations of fresh sputum and bronchial aspirates, and also for thick mucoid secretions
Spreading
A method of smear preparation that is useful for preparing smears of thick secretions such as serous fluids, concentrated
sputum, enzymatic lavage samples from the gastrointestinal tract, and blood smears.
Pull-Apart
A method of smear preparation that has an added advantage in that the cells may be examined without destroying their actual intercellular relationship, and without separating them from their normal surroundings
Touch Preparation (Impression Smear)
This method is normally utilized when a rapid diagnosis of the tissue in question is required, and is especially recommended when lipids and nervous tissue elements are to be demonstrated
Frozen Section
Very thin slices, around ______ thickness are cut from a fresh tissue frozen on a microtome with CO
10-15 u
Cryostat, a cold chamber is kept at an atmospheric temperature of?
-10° to -20° C.
The tissue for freezing should be _____ , and freezing should be done as quickly as possible
fresh
This can cause distortion of tissue due to ice crystal artifacts.
Slow freezing
The more commonly used methods of freezing include:
- Liquid nitrogen
- Isopentane cooled by liquid nitrogen
- Carbon dioxide gas
- Aerosol sprays
Generally used in histochemistry and during operative procedures, and is the most rapid of the commonly available freezing agents
Liquid nitrogen
The majority of non-fatty unfixed tissues are sectioned well at temperatures between?
-10°C and -25°C.
Solid structures and tissues must be preserved and carefully processed in the following order:
- Fixation
- Dehydration
- Clearing
- Infiltration (Impregnation)
- Embedding
- Trimming
- Section-Cutting
- Staining
- Mounting
- Labeling
The main disadvantage of using this freezing method is that - Soft tissue is liable to crack due to the rapid expansion of the ice within the tissue, producing ice crystals or freeze artifacts.
Liquid nitrogen
Liquid nitrogen overcools urgent biopsy blocks, causing damage to both block and blade if sectioning is done at
-70°C or below
