A wound specimen obtained from a person working with wool from a Caribbean island demonstrated a large gram-positive rod from a non- hemolytic colony with swirling projections on blood agar. The most likely method to demonstrate spores would be which of the following

Spores can be observed as intracellular refractile bodies in unstained cell suspensions. Also, they are commonly observed by staining with malachite green or carbolfuchsin. The spore wall is relatively impermeable, but heating of the preparation allows dyes to penetrate. Alcohol treatment then serves to prevent spore decolorization. Finally, the spores are counterstained.