Staining and Special Techniques for Microbiology Flashcards Preview

Microbiology First Aid USMLE Step 1 > Staining and Special Techniques for Microbiology > Flashcards

Flashcards in Staining and Special Techniques for Microbiology Deck (12):
1

Gram Stain

Most Bacteria

2

Which bacteria do NOT Gram stain well?
(These Rascals May Microscopically Lack Color)

- Treponema (too thin, use dark field microscopy and fluorescent antibody staining)
- Rickettsia (intracellular parasite)
- Mycobacteria (high lipids in cell wall are detected by carbolfuchsin in acid-fast stain)
- Mycoplasma (no cell wall)
- Legionella pneumophila (mostly intracellular, use silver stain)
- Chlamydia (intracellular parasite that lacks muramic acid in cell wall)

3

Acid-Fast Stain

Mycobacteria, nocardiae (modified)

4

Silver Stains

Fungi (eg, Pneumocystis), Legionella, H. Pylori

5

Periodic acid-Schiff stain (PAS)
- "PASs the sugar"

- Stains Glycogen, mucopolysaccharides; used to diagnose Whipple's disease (Tropheryma Whipplei)
- Fungi, Amebae

6

Mucicarmine Stain

Cryptococci

7

Giemsa Stain (Certain Bugs Really Try my Patience)

- Chlamydia, Borrelia, Rickettsiae, Trypanosomes, Plasmodium
- (Campylobacteria, Leishmaniae, Malaria, Parasites)

8

Antibody Probes

Viruses and Rickettsiae

9

Culture

All Classes of Infectious Agents

10

DNA Probes

Viruses, Bacteria, Protozoa

11

Ziehl-Neelsen (carbolfuchsin)

Acid-fast organisms (Nocardia, Mycobacterium)

12

India Ink

- Cryptococcus neoformans (mucicarmine can also be used to stain thick polysaccharide capsule red)