SPECIAL STAINS. PART 3

Question 1

Why was warthin starry staining produced

Answer 1

because some organisms does not stain well with gram staining

Question 2

What are examples of microorganism that does not stain well with gram staining

Answer 2

1. Spirochaetes (such as Helicobacter,
   Leptospira, Borrelia, and Treponema spp.),
2. Small bacilli (including
   Campylobacter, Bartonella, and Legionella
   spp.)

Question 3

Why is warthin starry called silver stain

Answer 3

because it is a silver nitrate-based staining method.

Question 4

Explain the general principle of warthin starry staining

Answer 4

1. Slides of tissue sections are immersed in an acidified aqueous solution of silver nitrate (optimum pH 3.5 to 4.0). Two reactions occur during this time. Firstly, large numbers of silver ions form bonds with protein molecules throughout the tissue. Secondly, smaller numbers of silver ions are reduced to
   silver atoms at specific sites in the tissue- within or on the surfaces of organisms. These metallic silver deposits are tiny particles known as “nuclei” (but these are not the same as cell nuclei).
2. Slides are immersed in a reducing solution that typically contains hydroquinone, gelatin, and a lower concentration of silver nitrate. This solution acts as a type of “developer”: the gelatin sequesters silver ions, slowing the rate at which they are reduced to metal by the hydroquinone. This slow reduction of the silver ions is catalyzed by the nuclei that were formed in the first step. Eventually, these tiny nuclei enlarge as more and more silver deposits on the organisms, until enough is present to make the organisms visible as black objects under the microscope.

Question 5

At the end product of the reaction what color will be organism stain

Answer 5

organisms stain dark brown to black.

Question 6

What will the lower concentrations of silver deposits stain

Answer 6

Golden brown

Question 6

Which disease diagnosis/investigations allows staining with warthin starry

Answer 6

1. leptospirosis (bacterial infection that spread from animals to humans)
2. cat scratch disease
3. Helicobacter-associated gastric cancer,

Question 7

What is warthin starry stain used in conjunction with

Answer 7

in conjunction with a Gram stain
to help answer questions that may arise after findings in routine H&E-stained
sections suggest bacterial involvement