Exercise 11: Other Differential Stains and Structural Stains

Question 1

Differential Staining

Answer 1

based on the composition of the cellular materials present in a cell
-selectively color different components of a cell or cell types

Question 2

Acid-fast stain

Answer 2

• colors cell types with mycolic acid

- can detect oocysts of the protozoan parasite Cryptosporidium; C. parvum –> waterborne diseases

Question 3

Mycolic acid

Answer 3

waxy component (lipid) found on some cell walls
-specific to Mycobacterium

Question 4

Negative Stain

Answer 4

-can be done to see the shape and size of bacteria that cannot withstand heat fixing
Ex. Treponema –> causes syphilis

• background is stained leaving cells and other extra cellular components (capsules) unstained
• contain chromogens (acidic)

Question 5

Capsule Stain

Answer 5

-similar to negative stain, but has the ability to differentiate cells that have the ability to produce extracellular capsules (which are heat sensitive)
Ex. Bacillus anthracis –> anthrax ; Streptococcus pneumonia (pneumonia)

Question 6

Flagella Stain

Answer 6

• special staining increases diameter of flagella
• Monotrichous: single flagellum
• Amphitrichous: flagella at both ends of cell
• Lophotrichous: tufts of flagella at end of cell
• Peritrichouse: flagella around entire cell surface