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trypan blue

British  
/ ˈtrɪpæn, ˈtrɪpən, trɪˈpæn /

noun

  1. a dye obtained from tolidine that is absorbed by the macrophages of the reticuloendothelial system and is therefore used for staining cells in biological research

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of trypan blue

so called because it is trypano-cidal : see trypanosome , -cide