Fundamentals Of Microbiology 10th Edition by Jeffrey Pommerville

Exercise 22

A student is performing the Gram stain technique on a mixed culture of gram-positive and gram-negative bacterial cells. In reaching for the counterstain in step 4, he inadvertently takes the methylene blue bottle and proceeds with the technique. What will be the colors of gram-positive and gram-negative bacteria at the conclusion of the technique
Courtesy of Janice Hanley Carr/CDC.