DEMONSTRATION OF BACTERIAL CAPSULES BY NEGATIVE STAINING METHOD
Reagents –
10 gm/dl nigrosine solution.
Sample –
A given culture.
Procedure –
Transfer aseptically a loopful of culture on a clean and dry slide.
Mix it with a loopful of stain.
Make a smear by using a glass slide.
Allow it to dry slowly at room temperature (25°C ± 5°C).
Observe under oil immersion lens.
Results –
| Observation | Appearance |
|---|---|
| Background | Bluish black |
| Organisms | Colorless (hollow bodies) |





