How spore staining method works?

Spores are impermeable structures which makes them resistant to dying. Spore staining depends on increasing the permeability of the spore coat by heating to permit the dye in. Upon cooling the dye is trapped inside the spore and not allowed out. The primary dye malachite green is a relatively weakly binding dye to the cell wall and spore wall. In fact, if washed well with water, the dye comes right out of the cell wall, however not from the spore wall once the dye is locked in. That is why there does not need to be a decolorizer in this stain. Upon further treatment with Carbol Fuchsin, the Vegetative cell walls will pick up the counterstain carbol fuchsin and will be stained pink. Spores will be of a light green colour. The identification of spores is very important for the clinical microbiologist who is analyzing a patient's body fluid or tissue since there are not that many spore-forming genera. Spores have two major pathogenic spore-forming genera, Bacillus and Clostridium in which both can cause various types of lethal diseases such as anthrax, botulism, gangrene and tetanus.