2-staining methods

Question 1

Special staining like

Answer 1

capsule , spore

Question 2

Gram negative bacteria red due to

Answer 2

counterstaining with carbol fuchsin

Question 3

staining steps

Answer 3

crystal violet for 1-2 minute.
o Pour it off then wash with water.
oiodine solution for 1-2 minute.
o Gently wash with water.
o Decolorize by 95% alcohol and rock the slide from side to side
and pour it off. Reapply alcohol till no violet color comes off.
o Wash with water
o Counterstain with diluted carbol fuchsin for 1 min. ((safranin))
o Wash with water.
o Place the film at angle to air dry

Question 4

Acid fast organism:

Answer 4

organisms resist “decolorization” by acid and/ or methanol

Question 5

steps of nehil zhlin

Answer 5

Primary dye : carbol-fuchsin
* Acid fast organism stains: Red
* Non Acid fast organism stains: Red
* After Decolorization with acid alcohol
* Acid fast organism stains: Red
* Non Acid fast organism stains: Colourless
* Counter stain with methylene blue:
* Acid fast organism stains: Red
* Non Acid fast organism stains: Blue