AFB

Question 1

sputum smear.

Answer 1

2x3 cm

Question 2

This is recommended when the
smear has not been prepared from sodium hypochlorite (bleach) treated sputum and will not be stained immediately. M. tuberculosis is killed by bleach and during the staining process. Heat fixation of untreated sputum will not kill M tuberculosis whereas _______ is bactericidal.

Answer 2

Alcohol-fixation

Question 3

When the tap water is not clean, wash the smear with

Answer 3

filtered water or clean boiled rainwater.

Question 4

Ziehl-Neelson

Answer 4

Primary stain: Carbol Fuchsin
Mordant: Steam
Decolorizer: Acid Alcohol, 3% HCl, 95% Ethanol
Counter Stain: Methylene Blue

Question 5

Kinyoun

Answer 5

Primary stain: Carbol Fuchsin
Mordant: Tergitol or 10% Phenol
Decolorizer: 3% HCl, 95% Ethanol
Counter Stain: Methylene Blue

Question 6

Screening:
Confirmatory:

Answer 6

Screening: HPO
Confirmatory: OIO

Question 7

Most preferred method for AFB

Answer 7

Rhodamine-Auramine

Question 8

Doesn’t have mordant because it has high affinity to lipid content in Acid-Fast organisms

Answer 8

Rhodamine-Auramine

Question 9

Rhodamine-Auramine

Primary stain:
Decolorizer:
Secondary Stain:

Answer 9

Primary stain: Rhodamine-Auramine
Decolorizer: 0.5% Acid Alcohol
Secondary Stain: 0.5% KMno4 or Potassium Permanganate

Question 10

Methods for Decontamination & Digestion for Mycobacteria

Answer 10

1. N-acetyl-L-Cysteine (NALC) + NaOH (2-4%) + Na Citrate = BEST
   ● NALC - Digesting / Mucolytic agent
   ● NaOH - Decontaminating agent
2. Trisodium phosphate and benzalkonium chloride (Zephiran)
3. Dithiothreitol and NaOH