A primary stain helps in the staining of the endospore. The process of endospore staining follows a general staining procedure and uses three kinds of stain. We can practice endospore staining by employing one of the two methods given in the figure below. Ovoid: An endospore appears small and egg-shaped.Spherical: The endospore appears small and pear-shaped.Elliptical: An endospore appears long or elongated.The structure of endospore also varies from individual to individual bacterial cell, but commonly they are of three types: Sub-terminal: The location of an endospore is between the central and terminal position of the vegetative cell.Terminal: The location of an endospore is towards an edge of the vegetative cell.Central: The location of an endospore is towards the centre of the vegetative cell.The position of endospore is different in different bacterial species, but commonly they exist in the following three types:

During germination, endospore loose resistance towards heat and staining. The Ca-DPA complex provides heat resistance to an endospore. DPA resides within the endospore core and exists in combination with a large amount of calcium (Ca-DPA complex). They can resist the boiling temperature for a few hours and heat treatment of 80 degrees Celsius for 10 minutes.Įndospores consist of a colossal amount of DPA (Dipiclonic acid), which constitutes about 10-15% of the spore’s dry weight. They are resistant to extreme physical conditions (like radiation, heat and desiccation, etc.) and chemical conditions (like staining, disinfection, etc.). The endospores are thick, dormant, metabolically inactive, and the refractile bodies produced by the few genera of the bacteria like Bacillus and Clostridium species.Įndospores can remain in a resting phase or dormant state before they germinate into new individuals. It is the unique structure of the bacteria, which forms during the unfavourable conditions approximately within 6-8 hours. These are the structures that form within the cell. Endospores can be stained by employing the two methods, namely Dorner’s method and Schaeffar and Fulton’s method. Escherichia coli, Salmonella sp etc., are examples of non-endospore formers. Clostridium perfringes, Bacillus cereus, Sporosarcina sp etc., are examples of endospore formers. Content: Endospore StainingĮndospore staining is a unique staining method, which discriminates between the two major groups of bacteria (spore formers and non-spore formers) by selectively staining the endospore against the vegetative cell. The main objective of endospore staining is to differentiate the bacterial endospore from the vegetative cell, which allows us to distinguish between the endospore formers and non-endospore formers.

Spore definition