Bacterial cells with thick peptidoglycan and numerous teichoic acid cross-linkages are Gram stained. The organisms stain pink. Which one of the following statements explains this discrepancy?

Answer: Thick walled bacterial cells with numerous techoic acids stain purple not pink on gram staining.

These are gram negative bacyeria ehich stain pink and gram positive bacteria stained purple.

Explanation:

Gram staining is a process of staining the cell walls of the bacteria to differentiate them from each other. Gram positive bacteria have cell walls composed of thick layers of peptidoglycan and techoic acid and they retain the crystal voilet dye and stain pruple when subjected to a Gram stain procedure. For eg staphylococcus species. Gram negative bacteria have cell walls with a thin layer of peptidoglycan and they do not retain the dye and stain pink. For eg neisseria species.

There are many other bacteria which are not stained by gram stain, because they either lack cell wall or have thin cell walls or are intracellular organisms.