Heat-Forced Dye Penetration Through a Spore Coat

Why an endospore's dense protective coat resists dye at room temperature but becomes briefly permeable enough under heat to trap the dye permanently inside.

References

• Schaeffer, A.B., Fulton, M.D. "A Simplified Method of Staining Endospores." Science 77, no. 1990 (1933): 194–196.