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Flashcards in Acid Fast Stain Deck (14):
0

Triple Sugar Iron:
- contains how many carbohydrates?
- what is the indicator? Its goal?
- what does Yellow color indicate? Red pink color?

- this medium contains 3 carbohydrates and differentiates Bac on fermentation of glucose, sucrose and lactose.
- The indicator is phenol red. To monitor the pH.
- Yellow in acid pH. Pink red in alkaline pH

1

TSI Test Result: what do these colors of tube mean?
- yellow
- pink red
- black

- entire tube is "Yellow", Bac fermented the glucose ( yellow buttom) and at least one of the other sugars,sucrose or lactose or both ( yellow slant). (Bac eat all 3 sugars).
- Pink red, Bac can only eat glucose, but not others 2 sugars. It has to break down peptones to produce ammonia. Then convert the pH
To alkaline and turns the agar pink red.
- H2S is produced, black color is observe b/c Bac fermented glucose( yellow butt), but also used peptones( pink red slant)

2

TSI Test:
- hoe to know the presence of "Gas" in tube?

- bubbles, cracks or agar up the tip.
- Breaks or air space in agar

3

SIM Test:
- what happen when adding Kovac's agent to SIM tube with Indole?
- motility : black? Yellow?
UREA Test:
Pink
Peach

-Tube: Kovac's + Indole = turns cherry red! indicating the presence of "Rosindole".
- Black (motile) and Yellow (non- motile).
Urea test:
Pink red:positive
Peach: negative

4

What is the Acid Fast Stain used for?

- It is a differential stain that detects the presence or absence of my colic acid.

5

What is a mycolic acid?

Mycolic acid is a waxy hydrocarbon over 80 *C in length

6

-Mycolic acid is sometimes referred to what?
-What is mycolic acid % of dry weight of the mycobacterium?

- Cord Factor which results in clumping and aggregating of Bac cells.
- 50%

7

What is the primary dye of a phenolic compound?

A phenolic compound uses "carbolfuchsin" as a primary dye which is a lipid soluble, concentrated stain.

8

Why is phenolic acid used for?

Phenolic acid allows to penetrate the huge carbohydrate.

9

What is the role of mycolic acid?

It gives lipids a higher affinity for carbolfuchsin
Resists decolonization with acid alcohol.

10

If Bac have mycolic acid, it turns into what color? If not? What color

-(+) pink / red : presence of mycolic acid ( fast acid mycobacterium)
- (-) blue: no presence of mycolic acid ( staphylococcus). Bac that r not acid fast are easy to decolorized by acid fast decolonization step and stain with the counterstain methylene blue.

11

What Bac causes tuberculosis ? Leprosy?

-Mycobacterium tuberculosis. 1/3 population of earth infected
-Mycobacterium leprae.

12

Procedure:
Agar plate culture of mycobacterium smegmatis ans staphylococcus aureus.

- Drop the circle on the slide and add a drop of Saline to the center
-Flame a loop and let it cool
- Take a small amt of a mycobacterium and spread out in to the saline. Flame the loop.
- in the same smear, mix a small amt of staphylococcus with sterile loop. Flame the loop n return it.
- let it air dry or dry above the incinerator.
- cover the smear area with carbolfuchsin for 5 min
-wash with distille water
- Decolorize with the acid alcohol for 5 sec
- immediately add water to stop decolonization
- Add methelyne blue counterstain for 30 sec
- wash the counterstain off
- Dry the slide with bibulous paper.
- Observe under oil immersion.

13

Acid fast mycobacterium will appear? Staphylococcus?

Pink
Light blue