MacConkey (MAC) agar is used to
A) differentiate between hemolytic and nonhemolytic gram-negative rods.
B) show the clear, pinpoint colonies of Haemophilus influenzae.
C) demonstrate the large, pink colonies of Neisseria meningitidis.
D) differentiate between lactose fermenters and lactose nonfermenters.

Question

Quizplus · Accepted Answer

MacConkey agar is a selective and differential medium that helps to differentiate lactose fermenters (which produce acid and cause pink colonies) from lactose nonfermenters (which do not produce acid and appear colorless on the medium). It is commonly used to isolate and identify enteric bacteria, such as Escherichia coli and Salmonella typhimurium, from clinical and environmental samples.

MacConkey (MAC) Agar Is Used to