The process of adding a dye to a bacterial culture



Basic dye—possess a positive charge
Acidic dye—possess a negative charge
Remember, bacteria posses a slight negative charge on their surface



Use only one dye
For the purpose of viewing bacterial shapes and arrangements

Simple Stain the following:
1)
2)
E. coli
S. aureus
3) A colony from the “Microbes in the Environment” plate




Simple Staining (shapes and arrangements)
Differential Staining (Gram reactions)
Special Staining (Capsule, flagella, spores)





Prepare smear of bacterium
Air dry
Heat fix the bacteria to the slide
(release of “sticky” proteins from the cell surface of the bacteria adheres the bacterial cell to the slide)
Apply crystal violet to the smear; let stand 45 seconds




Rinse with distilled water or tap water
Blot dry with bibulous paper
View using microscope

Page 49

Page 54

Page 55
Methylene blue
Crystal Violet
Fuchsin
Simple stains allow visualization of
Shapes
Arrangements
Proteus vulgaris
Staphyloccocus aureus
Bacillus cereus

Fracisella tularensis
Causitive agent of Rabbit fever
Methylene blue stain
Sacharromyces cerevisiae
(Brewer’s yeast)
Methylene blue stain

Bacillus anthracis (anthrax)
Gram positive
Crystal violet stain
Campylobacter jejuni (traveler’s diarrhea)
Gram negative
Fuchsin stain