I. ˈkau̇ntə(r)+ˌ- noun
Etymology: counter- + stain (n.)
: a stain used to color parts of a microscopy specimen not affected by another stain ; especially : a cytoplasmic stain used to contrast with or enhance a nuclear stain
II. | ̷ ̷ ̷ ̷+ transitive verb
Etymology: counter- + stain (v.)
: to stain (a tissue or microscopy specimen) with an additional usually contrasting color