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