Lab Report
BACTERIAL ENDOSPORE STAINING

Introduction:
Bacterial endospores are small oval or spherical structures that are resistant to high temperatures, radiation, dessication, and chemical agents such as disinfectants. The spores are produced inside the bacterial cell thus getting the name endospore and they are formed as a survival mechanism in response to adverse conditions. The vegetative cell gives rise to the endospore which is stimulated by the depletion of nutrients. The spores are inactive cells in dormant phase. They are encased in three heavy layers which are highly resistant to damage. The spores can be centrally, sub- terminally, or terminally located. The size and location of the spore within the vegetative cell are significant in differentiating organisms. The Schaeffer- Fulton Spore staining technique is a differential staining method where malachite is the primary stain which stains the endospore green while safranin is the counter stain that stains the vegetative part of the bacterial pink such that both the structures can be viewed under the microscope with ease.
Materials and Methods:
The bacteria used for staining endospore was Bacillus subtilis, and the staining technique used was Schaeffer- Fulton Spore stain. A smear of the bacterial species was prepared. The smear was air- dried and heat fixed. Then a small piece of paper was taken with the width of the paper slightly smaller than that of the glass slide. A beaker with water was boiled and a staining rack was put above the steam to hold the glass slide. The slide was then flooded with malachite green and placed on top of the rack so that the stain would not dry. The slide was constantly flooded with malachite green while being moistened by steam. The slide was allowed to cool to prevent it from breaking. The slide was drained and rinsed with water for 30 seconds. The slide was then stained with Safranin for 1 minute. Again, the slide was drained and washed with water after which it was blotted and let to air dry
Results:

Figure: Bacillus subtilis endospore staining
Discussion:
The microorganisms were spherical in shape. The mother cells were pink in color and the endospores were green in color. The endospores were spherical and centrally located inside the mother cell. There were numerous cells with endospores, a few of which were swollen. Also, vegetative cells that did not have endospores were present and free endospores were abundant.