wk 1-3

Question 1

Function: Cuts thin sections of paraffin-embedded tissue blocks.

Answer 1

microtome

Question 2

Contribution: Provides uniform, thin slices of tissue, which are essential for microscopic examination and accurate diagnosis.

Answer 2

microtome

Question 3

Function: Automates the process of dehydrating, clearing, and embedding tissue samples in paraffin.

Answer 3

tissue processor

Question 4

Contribution: Ensures consistent and efficient processing of tissue samples, preparing them for embedding and sectioning.

Answer 4

tissue processor

Question 5

Function: Melts and molds paraffin around tissue samples.

Answer 5

Embedding Station

Question 6

Contribution: Facilitates the embedding of tissue in paraffin blocks, which are necessary for cutting into thin sections.

Answer 6

Embedding Station

Question 7

Function: Applies various dyes and stains to tissue sections to highlight different cellular components and structures.

Answer 7

Staining Systems (e.g., Automatic Stainers)

Question 8

Contribution: Enhances tissue contrast and allows for visualization of specific features, aiding in the diagnosis.

Answer 8

Staining Systems (e.g., Automatic Stainers)

Question 9

Function: Applies a coverslip to stained tissue sections mounted on slides.

Answer 9

Coverslipper

Question 10

Contribution: Protects the stained tissue sections and provides a clear surface for microscopic examination.

Answer 10

Coverslipper

Question 11

Function: Magnifies and visualizes tissue sections for detailed examination.

Answer 11

Microscope

Question 12

Contribution: Allows pathologists to observe cellular and tissue structures, diagnose diseases, and assess the severity of conditions.

Answer 12

Microscope

Question 13

Function: Cuts frozen tissue sections for immediate analysis.

Answer 13

cyrostat

Question 14

Contribution: Enables the rapid preparation of tissue sections for intraoperative consultations and some specialized studies.

Answer 14

Cryostat

Question 15

Function: Maintains slides at a specific temperature to prevent distortion or damage.

Answer 15

Histology Slide Warmer

Question 16

Contribution: Ensures that tissue sections remain in optimal condition during staining and analysis.

Answer 16

Histology Slide Warmer

Question 17

Function: Melts paraffin wax used for embedding tissue samples.

Answer 17

Paraffin Bath

Question 18

Contribution: Provides a controlled temperature environment for melting and maintaining paraffin in a liquid state.

Answer 18

Paraffin Bath

Question 19

Function: Cleans slides and glassware used in histological procedures.

Answer 19

Washing Stations

Question 20

Contribution: Ensures that all equipment is free of contaminants and residues, which is crucial for accurate staining and analysis.

Answer 20

washing station

Question 21

Function: Digitizes tissue slides for digital analysis and storage.

Answer 21

Slide Scanner

Question 22

Contribution: Facilitates remote consultations, archival of samples, and integration with digital pathology systems for enhanced analysis.

Answer 22

Slide Scanner

Question 23

Function: Provides a controlled environment to protect users from exposure to hazardous materials and to prevent contamination of the samples

Answer 23

Biosafety cabinet

Question 24

Contribution: Ensures that potentially infectious or hazardous substances are contained within the cabinet, safeguarding both the technician and the integrity of the samples.

Answer 24

bsc

Question 25

aim of Histopathological technique

Answer 25

The aim is to preserve the microscopic anatomy of the tissue and make iy hard to that the section can be made

Question 26

describes the various steps required to take the tissue from fixation to the state where it is completely infiltrated with a suitable histological wax and can be embedded ready for section cutting on the microtome.Once the tissue has been fixed, it must be processed into a form in which it can be made into thin microscopic sections.

Answer 26

tissue processing

Question 27

tissue processing in order to

Answer 27

n order:
Fixation
Decalcification (optional)
Dehydration
Clearing
Impregnation (Infiltration)
Embedding
Trimming
Section-Cutting (Microtomy)
Staining
Mounting
Labelling

Question 28

fixation

Answer 28

Tissue is fixed to preserve its structure.
USE: Formalin or formaldehyde solution
Do asap
Formalin, usually as a phosphate-buffered solution, is the most popular fixative for preserving tissues that will be processed for paraffin embedding.
Following fixation, appropriately trimmed specimens are placed in suitable labelled cassettes (small perforated baskets) to segregate them from other specimens.
Formalin-fixed, paraffin-embedded tissues may be stored indefinitely at room temperature, and nucleic acids (both DNA and RNA) may be recovered from them decades after fixation.

Question 29

dehydration

Answer 29

Remove water from the tissue using increasing concentrations of alcohol
Use: acetone or isopropanol
Gradual replacement of water with alcohol to prevent tissue distortion.
Because melted paraffin wax is hydrophobic (not miscible with water), most of the water in a specimen must be removed before it can be infiltrated with wax
Fatty tissues such as breast or lipoma may be inadequately processed in what is normally a successful schedule for other tissues.
To ensure complete dehydration, a superior fat solvent such as acetone or isopropanol should be added before the final absolute ethanol, and chloroform or trichloroethane used as the transition solvent.

Question 30

clearing

Answer 30

Remove alcohol with a substance miscible with paraffin wax and ethanol
Common clearing agent: Xylene
Many clearing agents impart an optical clarity or transparency to the tissue due to their relatively high refractive index (makes tissue transparent)
Removes fat
In these stages, the ethanol is gradually replaced with xylene and when the tissue is embedded, the xylene will then be replaced by the molten paraffin wax

Question 31

Infiltration / impregnantion:

Answer 31

Replace clearing agent with embedding medium:
Typically, paraffin is used.
Clearing agent is completely removed from the tissue and replaced by a medium that gives firm consistency to the specimen (fills cavities in tissue)
The cleared tissue is infiltrated with a suitable histological wax (usually paraffin) which is liquid at 60°C and then allowed to cool to 20°C in order to solidify into a consistency that allows sections to be cut.

Question 32

embedding

Answer 32

Out of casting / blocking out
Encoding tissue in a medium and allowing medium to solidify
Uses paraffin wax
End product: tissue block
Embedding mould: can be made of stainless steel, ceramic, paper, plastic, or aluminium foil. )depends on microtome used for sectioning)
Double embedding is usually done

Question 33

trimming

Answer 33

Excess plastic surrounding the tissue must be trimmed away in a fashion that will yield a square or rectangular sections.
Trim the capsule while viewing under the dissecting microscope using old glass knives or knives not suitable for sectioning.
The capsule mold must be trimmed to a pyramid where the pyramid tip and sides are exposed tissue. The angle of the pyramid sides (called facets) should be about 45°.

Question 34

Section cutting/trimming

Answer 34

Uses microtome
Paraffin embedded tissues are trimmed and cut into uniformly thin slice or sections to facilitate studies under the microscope
Warm water bath removes wrinkles from sections

Question 35

Creates contrast in tissues, making them more visible in the microscope
Slides are dried at 60C
Tissue is rehydrated to prepare it for staining

Answer 35

Staining