Microbio Lab Quiz 5

Acid Fast Stain

The genus of bacteria that have cell walls that are high in fatty wax content 

Mycobacterium 

Tuberculosis

Is caused by Mycobacterium

Why are mycobacterium hard to stain?

Because of the presence of mycolic acid and high glycolipid content in the cell wall (it makes the cell waxy and hydrophobic)

Dyes such as carbolfuchsin can penetrate the waxy cell wall if what is applied?

Heat and Phenol

Once the cell is stained, mycobacterium resists decolorization even if harsh agents such as BLANK are used 

Acid-Alcohol 

A bacterial cell that is acid-fast, stains (color) BLANK, has a cell wall made of BLANK, and belongs to the genus BLANK

1. Red

2. Mycolic Acid

3. Mycobacterium

What is done to the smear when the carbolfuchsin is applied in the Ziehl-Neelsen staining technique?

Heating

Why does the carbolfuchsin penetrate the acid fast cell walls during the Kinyoun staining technique?

Fuchsin is more soluble in Phenol

Primary Stain for Acid Fast procedure

• Reagent- Carbolfuchsin

• Staining time- 10 minutes

• Color of acid fast cells- Red

• Color of non-acid fast cells- Red

Decolorizer for Acid Fast procedure

• Reagent- Acid-Alcohol

• Staining time- Until runoff is colorless

• Color of acid fast cells- Red

• Color of non-acid fast cells- Colorless

Counterstain for Acid Fast procedure

• Reagent- Methyl Blue 

• Staining time- 60 seconds 

• Color of acid fast cells- Red 

• Color of non-acid fast cells- Blue