Ziehl-Neelsen stain is a type of staining technique commonly used in microbiology to identify acid-fast bacteria. Other synonyms for this staining method include ZN stain, Acid-Fast stain, and Kinyoun stain. These synonyms refer to different variations of the Ziehl-Neelsen staining method, which differ mainly in the strength of the decolorizing agent used. Other related staining techniques for identifying different groups of bacteria include Gram staining, which is used to identify gram-positive and gram-negative bacteria, and India ink staining, which is used to visualize encapsulated organisms. In summary, there are several synonyms for Ziehl-Neelsen staining, each with its subtle differences in methodology.