Context: The Gram stain, developed in 1884 by Hans Christian Gram, characterises bacteria based on the structural characteristics of their cell walls. The thick layers of peptidoglycan in the "Gram-positive" cell wall stain purple, while the thin "Gram-negative" cell wall appears pink. By combining morphology and Gram-staining, most bacteria can be classified as belonging to one of four groups (Gram-positive cocci, Gram-positive bacilli, Gram-negative cocci and Gram-negative bacilli). Some organisms are best identified by stains other than the Gram stain, particularly mycobacteria or Nocardia, which show acid-fastness on Ziehl–Neelsen or similar stains. Other organisms may need to be identified by their growth in special media, or by other techniques, such as serology.

Question: What was developed by Hans Christian  Gram?
Answer: The Gram stain

Question: What year was the Grahm stain was developed?
Answer: 1884

Question: What color do Gram positive bacteria cell walls turn to after being stained?
Answer: purple

Question: What color is typical for Gram-negative bacteria after staining?
Answer: pink

Question: What stain shows better test results on Norcadia bacteria?
Answer: Ziehl–Neelsen