How is Mycobacteria categorized in terms of gram staining?

Mycobacteria are categorized as gram-positive bacteria, but they exhibit a unique characteristic that complicates their identification through routine gram staining. They possess a thick, waxy cell wall rich in mycolic acids, which prevents the uptake of purple dye used in the gram staining process. This property typically makes them appear pink after the acid-fast staining procedure rather than the characteristic purple of gram-positive bacteria.

In standard gram staining, Mycobacteria might not retain the crystal violet stain effectively and might not appear distinctly colored, leading to confusion in categorization. Hence, while they are classified as gram-positive due to their cell wall structure, they require specific staining techniques, like the acid-fast stain, to visualize them properly in a laboratory setting.

The other choices do not accurately describe the classification of Mycobacteria. They cannot be considered gram-negative, which would indicate a thinner peptidoglycan layer and an outer membrane, lacking in Mycobacteria. The terms "neither" and "both" do not fit appropriately in this context because they do have a defined categorization which is primarily gram-positive, notwithstanding the unique complications presented by their cell wall structure.