Gordan and Sweets Stain

Question 1

What is the purpose of the silver impregnation method?

Answer 1

Demonstration of the argyrophilic reticulin fibres of connective tissues

This method highlights the presence of specific connective tissue fibres using silver staining techniques.

Question 2

What are argyrophilic properties?

Answer 2

Fibres can bind silver but require a chemical reducer (developer) to visualize them

This property is crucial for the effectiveness of the silver staining process.

Question 3

What is the role of potassium permanganate in the silver impregnation method?

Answer 3

Oxidation step that enhances fibre reactivity by creating aldehyde groups

This step is essential for making the reticulin fibres more reactive to silver.

Question 4

What does oxalic acid do in the silver staining process?

Answer 4

Bleaches colour produced by potassium permanganate

This step helps to eliminate unwanted colour that could interfere with visualization.

Question 5

What is the function of iron alum in the silver impregnation method?

Answer 5

Targets and binds to retinculin fibres, sensitizing them which enhances their ability to bind to silver

This sensitization is critical for achieving effective staining results.

Question 6

How does the silver stain interact with reticulin fibres?

Answer 6

Binds to aldehyde-rich reticulin fibres, causing silver ions to aggregate

This aggregation is what leads to the visible black staining of the fibres.

Question 7

What is the role of 10% Formalin in the silver staining process?

Answer 7

Reducing agent that converts silver ions into visible metallic silver

This step is crucial for the staining process, resulting in the black colour of stained reticulin.

Question 8

What is the purpose of gold chloride in the staining process?

Answer 8

Enhances contrast and prevents fading by replacing silver deposits with gold

This ensures a crisper black stain, improving the quality of visualization.

Question 9

What is the function of sodium thiosulphate (Hypo) in the process?

Answer 9

Fixing step that removes excess unbound silver/gold to prevent nonspecific background staining

This step is important for ensuring the clarity of the stained sample.

Question 10

What is the purpose of light green in the silver impregnation method?

Answer 10

Counterstaining to provide background contrast

This helps to enhance the visibility of the stained reticulin fibres.

Question 11

What are the different elements of gordan and sweets stain? (8)

Answer 11

1. Potassium permanganate
2. Oxalic acid
3. Iron alum
4. Silver solution
5. Formalin
6. Gold chloride
7. Sodium thiosulphate (hypo)
8. Light green