Metachromatic Granules Stain

 

Principle:

The size of Corynebacterium diphtheriae is very variable, essentially rod-shaped but often showing irregular expansion at one end. Cells frequently lie in small clusters at acute angles to each other in V, L or Y shapes. Gram positive but readily decolorized, non-motile, non-capsulate, non-sporing.

Strains are distributed as beans and stained unevenly. With Metachromatic Granules Stain, deeply stained granules known as metachromatic granules, are found on one side or both sides of diphtheriae.

 

Specifications:

Contents	2vials×20ml/Kit	Components
Solution A	1vial×20ml	Toluidine Blue
Solution B	1vial×20ml	Potassium iodide

 

Methods:

1. Fix smears on flames, add solution A to stain for 3~5 minutes and rinse with water.

2. Add solution B to stain for 1 minute and rinse with water.

3. Dry and observe microscopically.