FRESH TISSUE EXAMINATION Flashcards
Selected tissue specimen is immersed in a watch glass containing isotonic salt solution, carefully dissected or separated
Teasing or dissociation
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)
Smear preparations are useful in
Cytological examinations, particularly for cancer diagnosis
More tedious than streaking, but has the advantage of maintaining cellular interrelationships of the material to be examined.
Spreading
With an applicator stick or 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
Recommended for smear preparations of fresh sputum and bronchial aspirates, and also for thick mucoid secretions.
Spreading
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
Done by placing a drop of secretions or sediment upon one slide and facing it to another clean slide. The material disperses evenly over the surface of the two slides
Pull-Apart
The surface of a freshly cut piece if tissue is brought into contact and pressed on to the surface of a clean glass slide, allowing the cells to be transferred directly to the slide
Touch imprint (impression smear)
Advantage of Touch imprint (impression smear)
Cells may be examined without destroying their actual intercellular relationship and without separating them from their normal surrounding
Utilized when rapid diagnosis of the tissue in question is required
Frozen section
Recommended when lipids and nervous tissue elements are to be demonstrated
Frozen section
The more commonly used method 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 commonly available freezing agents
Liquid nitrogen
Main disadvantage of Liquid nitrogen
Soft tissue is liable to crack due to rapid expansion of the ice within the tissue
Over cools urgent biopsy blocks
