Congo red

noun

, Chemistry.

1. a water-soluble powder, C 32 H 22 O 6 N 6 S 2 Na 2 , one of the Congo colors that is not acid-fast or lightfast: used chiefly as a dye, biological stain, and chemical indicator.

Congo red

noun

1. a brownish-red soluble powder, used as a dye, a diagnostic indicator, a biological stain, and a chemical indicator. Formula: C 32 H 22 N 6 O 6 S 2 Na 2

Word History and Origins

Origin of Congo red¹

First recorded in 1880–85

Example Sentences

The leak turned a tributary of the River Congo red and killed huge numbers of fish, which some people ate, said Environment Minister Eve Bazaiba.

From BBC

As defined by pathologists1 who document amyloids in numerous diseases, the fibrils must be deposited in body tissues and fluoresce a green–yellow colour when stained with the dye Congo red and viewed between crossed polarizers.

From Nature

Amyloid is defined pathologically by the demonstration of green birefringence on binding of the dye Congo red and biophysically by a cross-β fibre diffraction pattern. b, Models of recombinant PrP fibrils and ex vivo prions.

From Nature

Amyloid is defined pathologically by the demonstration of green birefringence on binding of the dye Congo red and biophysically by a cross-β fibre diffraction pattern. b, Models of recombinant PrP fibrils and ex vivo prions.

From Nature

When doused with Congo red, a standard pathology stain, and illuminated with polarized light, the Alzheimer's plaques — just like scrapie plaques — displayed an apple-green shimmer, a prismatic sign of the hydrogen bonds that held their fibrils tightly together.

From Nature