- a crystalline derivative of thiazine used as a violet dye to stain microscope specimens
- any of a class of related dyes
C19: by shortening, from ergothioneine, a crystalline betaine found in ergot and blood
- A dark-green powder that turns water purple when mixed in solution, used as a basic stain in histology for chromatin and mucin because of its metachromatic properties.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.