Question

Yesterday, you inoculated two separate overnight cultures ofEscherichia coli and Staphylococcus aureus, respectively. Today inthe morning, you realize that you forgot to label the two cultures.Your lab instructor suggests to compare the two cultures under themicroscope and to identify the cultures by carrying out theGram-stain procedure. Which of the following statements is NOTtrue?

A. The Alcohol is used during the Gram-staining procedure tostabilize the crystal violet in gram-negative bacteria.

B. B and D are not correct.

C. Gram staining procedure will lead to purple color ingram-positive bacteria due to the thick cell wall.

D. Staphylococcus aureus has a spherical morphology and formscluster, while Escherichia coli has a rod-shaped morphology. Afterthe Gram staining procedure, Staphylococcus aureus will remainpurple while Escherichia coli will appear pink.

E. Both species display spherical morphology and form cluster.After the Gram staining procedure, Staphylococcus aureus willappear pink while Escherichia coli remains purple.

F. B, C, D are not correct.