Special Stains- Capsule Flashcards
Purpose of capsule stains
allow gel like layer (capsules) around certain microbes to be seen since common dyes do not stain capsules well
How are capsules visible in capsule stain process?
The background is stained so capsules are visible against the dark background
Capsule stain technique and time
Use drop Nigrosin/India Ink/ Congo red , add bacteria +water, use second cleans slide to smear and create thin film, let air dry, Cover smear with crystal violet for 1 min, rinse w/ distilled water, air dy
The purpose of a cell’s “capsule” is
to protect the cell from its environment or predators
Capsules are composed mostly of
polysaccharides, and some polypeptides
bacterial capsules are non ionic meaning (not charged)
they have neither a positive or negative charge so dye wont adhere to them and background stain is needed
Results of capsule staining
capsule leaves clear halo around pink cell in a field of black
In capsule staining, there is
NO HEAT nor NO BLOT DRY