Endospores are surrounded by a highly resistant spore coat, The spore coat is highly resistant to excessive heat, freezing and
desiccation as well as chemical agents. More importantly, for identification, spores are resistant to commonly employed staining techniques; therefore alternative staining methods are required. Moeller staining involves the use of a steamed dye
reagent in order to increase the stainability of the spores;
Carbol fuchsin is the primary stain used in this method. Endospores are stained red, while the counterstain,
Methylene blue stains the vegetative bacteria blue.