Acridine dyes

Acridine dyes are derived from acridine
They have the general formula

 

The general formula shows the chromophore to be a quinoid ring. It should also be noted that the molecule is positively charged, shown on the nitrogen atom attached to the quinoid ring, and the dyes are consequently basic. There are a few dyes in this class that are used in histotechnology, but they tend to be for fairly specialised purposes which take advantage of their fluorescent characteristics. The commonest examples would be acridine orange and acriflavine.

 

Reference
R. D. Lillie.
Conn's Biological Stains
Williams & Wilkins, Baltimore, MD., U.S.A.