U1 LAB: INSTRUMENTATION Flashcards
Histopathologic Techniques
- Numbering
- Fixation
- Decalcification
- Dehydration
- Clearing
- Impregnation
- Embedding
- Blocking
- Trimming
- Sectioning
- Staining
- Mounting
- Labelling
Numbering is also known as?
Accessioning
This consists of the process: Recording, Logging and Encoding
Numbering
This must be immediately done unless stated by physician.
Fixation
Mineralized specimens include?
bones, deposits in brain (plaques)
This is only done in mineralized specimens.
Decalcification
This step is the removal of water, and uses 70 to 100% absolute ethanol.
Dehydration
This step makes the specimen more clear and transparent, with the use of clearing agents.
Clearing
This makes the specimen miscible to next media.
Clearing agents
Example of Clearing agents
Xylene / Xylol
Impregnation is also known as?
Wax Infiltration
This step refers to the formation of tissue blocks with embedding media.
Embedding
Most common embedding media
Paraffin
Blocking is only done with?
multiple / compound block
This step helps with the tissue block to be more fitted.
Trimming
This step requires the use of microtomy to produce tissue ribbons.
Sectioning
Most common stain in histopath
Hematoxylin & Eosin (H&E)
This step uses a mounting media and coverslip to prevent contamination.
Mounting
This step is a reminder to check if it is properly labelled and stored.
Labelling
Automated Tissue Processors include the following processes:
- fixation
- dehydration
- clearing
- wax impregnation
This tissue processor is characterized by the transfer of tissues, contained within a basket, through a series of stationary reagents arranged in-line or in a circular carousel plan.
carousel-type
Carousel-type processors
What is stationary?
reagents
Carousel-type processors
How many reagent positions can be programmed?
9-10
Carousel-type processors
How many wax positions can be programmed?
2-3
Carousel-type processors
Capacity
30-110 cassettes
T/F: In carousel-type processors, you may reuse the reagents.
True
This is characterized by processing fluids pumped to and from a retort in which the tissues remain stationary.
fluid-type
T/F: Fluid-type processors give out better results.
True
Fluid-type processors
What remains stationary?
tissues
Fluid-type processors
Reagent stations and temperatures
10-12, 30-45C
Fluid-type processors
Wax stations and temperatures
3-4, 48-68C
Fluid-type processors
Capacity
100-300 cassettes
Tissue Embedding Center
This is programmed 2 to 3 degrees higher than melting point of paraffin.
Paraffin Melting Chamber
Tissue Embedding Center
This is pressed to dispense melted paraffin (liquid).
Microswitch
Tissue Embedding Center
This is used for better orientation.
Pre-warming area
Tissue Embedding Center
This is used for the solidifcation of tissue blocks.
Cold orientation platform
This is a basic instrument used to cut sections at a predetermined thickness by sliding the block into a cutting tool which is fixed and attached to medicine.
Microtome
Microtomy is used for what step?
sectioning
Principle of Microtomy
- Spring balance teeth/pawl is brought in contact with ratchet feed wheel
- Ratchet feed wheel is connected to a micrometer screw which rotates
- Moves the tissue block at a predetermined distance towards knife for cutting at uniform thickness
Microtomy
Predetermined distance is dependent on?
thickness
Microtomy
Uniform thickness
5-10um
Microtomy
Specimen holder is also known as?
Chuck
Kinds of Microtome
- Rocking
- Rotary
- Sliding
- Freezing
- Ultrathin
This is the simplest among different types of microtome.
Rocking Microtome
Rocking Microtome
Other name
Cambridge rocking microtome
Rocking Microtome
Invented by?
Paldwell Trefall (1881)
Rocking Microtome
Consists of?
- heavy base
- two arms