"Table 2.5: Gram staining process. Gram-staining is a differential staining technique that uses a primary stain and a secondary counterstain to distinguish between gram-positive and gram-negative bacteria. (c) Rice University. OpenStax Microbiology. CC BY 4.0. https://openstax.org/details/books/microbiology. Figure 2.16: In this specimen, the gram-positive bacterium Staphylococcus aureus retains crystal violet dye even after the decolorizing agent is added. Modification of work (c) Nina Parker. CC BY 4.0. Figure 2.17: Ziehl-Neelsen staining has rendered these Mycobacterium tuberculosis cells red and the surrounding growth indicator methylene blue. (c) American Society of Microbiology. Redistribution authorized with attribution. Figure 2.18: India-ink was used to stain the background around these cells of the yeast Cryptococcus neoformans. (c) American Society of Microbiology. Redistribution authorized with attribution. Figure 2.19: A stained preparation of Bacillus subtilis showing endospores as green and the vegetative cells as pink. (c) American Society of Microbiology. Redistribution authorized with attribution. Figure 2.20: A flagella stain of Bacillus cereus, a common cause of foodborne illness, reveals that the cells have numerous flagella used for locomotion. Modification of work by Centers for Disease Control and Prevention. Public Domain. Table 2.6: Simple stains. Top: Modification of work by Centers for Disease Control and Prevention. Public Domain. Middle: Modification of Figure 1C in Danovaro, R., Dell’Anno, A., Pusceddu, A. et al. The first metazoa living in permanently anoxic conditions. BMC Biol 8, 30 (2010). https://doi.org/10.1186/1741-7007-8-30. CC BY"