Any one of a group of reddish to purplish dyes used in staining bacteria for microscopic observation and capable of killing various disease-causing microorganisms. Add fuchsin (acid magenta) is a mixture of sulfonated fuchsins; basic fuchsin (basic magenta) and new (trimethyl) fuchsin are basic histological dyes (basic fuchsin is also an antifungal agent).
A red dye that can be prepared in an acid or basic form.