A bacterial cell that contains an outer membrane and periplasmic space stains pink to red on Gram stain. Which one of the following statements explains this discrepancy?
a. The bacteria were subjected to too much alcohol during the decolorization process, causing the organism to absorb the pink-to-red dye.
b. The bacteria with an outer membrane and periplasmic space should not be Gram stained because of their cell wall content.
c. Something is wrong with the lot of stains and may be expired. The Gram stain rea-gents are most likely expired.
d. No discrepancy is present; organisms that contain an outer membrane and periplas-mic space should stain pink because of their cell wall composition.
D
Gram-negative organisms contain an outer membrane and periplasmic space and therefore should stain red to pink to red on Gram stain because of their cell wall composition.
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