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. No discrepancy is present; organisms that contain an outer membrane and periplasmic space should stain pink because of their cell wall composition. b. Something is wrong with the lot of stains and may be expired. The Gram stain reagents are most likely expired. c. The bacteria were subjected to too much alcohol during the decolorization process, causing the organism to absorb the pink-to-red dye. d. The bacteria with an outer membrane and periplasmic space should not be Gram stained because of their cell wall content.

a. No discrepancy is present; organisms that contain an outer membrane and periplasmic space should stain pink because of their cell wall composition.

Explanation:

Gram stain is the staining method used to differentiate bacterial species into two groups, gram-positive and gram-negative bacteria. Factors that will differentiate gram-positive from gram-negative include the coloration of bacteria, the composition and chemical and physical properties of cell walls. In these tests, bacteria that have an outer membrane and a periplasmic space are considered gram negative and pink in color (sometimes similar to red) due to their cellular composition. For this reason we can state that there is no discrepancy present in the bacteria exposed in the question; Because this bacterium has an outer membrane and a periplasmic space, then it is normal for the bacteria to turn pink due to its cell wall composition.