Serratia Marcescens

Micrococcus luteus

Ameba proteus

Plasmodium falciparum

Staphylococcus epidermidis

Bacillus megaterium

E Coli, Pseudomonas, and Myobacterium

Trypanosoma cruzi

Trichomonas Vaginalis

Paramecium

Bacillus megaterium

Steps of Gram Stain

1. Crystal Violet (Primary) 1 min

2. Iodine (Mordant) 1 min

3. Alcohol (Decolorizer) 5-10 secs

4. Safranin (Counterstain) 1 min

Acid Fast Stain

1. Carbolfuchsin (Primary) USE Bibulous Paper!

2. Heat (Mordant) 5-10 mins

3. Acid Alcohol (Decolorizer) 5-10 secs

4. Methylene Blue (Counterstain) 1 min

Endospore Stain

1. Malachite Green (Primary) USE Bibulous Paper!

2. Heat (Mordant) 5-7 mins

3. Rinse with Water (Decolorizer)

4. Safranin (Counterstain) 1 min

Gram Stain Positive Color and Why

Purple, Thick Peptidoglycan

Gram Stain Negative Color and Why

Red, Thin Peptidoglycan

Acid Fast Stain Positive Color and Why

Red, Contains Mycolic Cell Wall

Acid Fast Stain Negative Color and Why

Blue, Lacks Mycolic Cell Wall

Reason for Endospore Stain

To distinguish between metabolically active vegetative cells and dormant, resistant spores