Purpose: To differentiate between organisms that can produce endospores and those that cannot. Also allows differentiation based on the position of the endospore in the cell
Principle: Spores have a durable outer coating that is composed of the protein keratin. This keratin coat resists staining so in order to stain a spore the primary stain, malchite green, must be heated to drive the stain into the spores. Vegatative cells are then decolorized with water and 0.5% safranin is used to counterstain. Thus endospores are stained green, while vegetative cells are stained red.
The stain to the right shows a bacterium capable of endospore production.A. Vegetative Cell
B. Endospore
