Quinone-imine Dyes 



131 



mixture of the two gave good results. In other words he did about 

 the same thing that the Commission now often recommends stain 

 companies to do. 



Grlibler also sold other grades of safranin, none of which seem to 

 have any special significance for biological purposes. One of these 

 denoted "Safranin pur" was found on testing to be a more violet 

 dye, apparently methylene violet (C. I. No. 842). 



Safranin O is one of the most important nuclear stains known to 

 the histologist. The botanist finds it especially valuable, as it 

 brings out lignified and cutinized tissues in vascular plants, and 

 can be employed in combination with a variety of contrast stains; 

 it is valuable as a protein stain in plants, and can be used to stain 

 spore coats. The cytologist makes use of it in the Benda technic 

 to stain chromatin in combination with light green as a contrast 

 stain; and even more widely in the Flemming triple stain, in which 

 it is employed as a chromatin stain, together with gentian violet 

 and orange G. The bacteriologist has some use for it, especially 

 as a counterstain in the Gram technic. 



PROCEDURES RECOMMENDED BY THE COMMISSION IN WHICH THIS STAIN IS USED 



l25 amethyst violet 



Synonyms: Heliotrope B. Iris violet. 

 This dye is tetra-ethyl pheno-saf ranin : 



CH3CH. 11 I I CH.CH, 



\ /\/~N=\/\ / 



N / \ N 



/ /\ CI \ 



CH3CH. 1 I CH.CHj 



C. I. NO. 847 



C26H31N4CI; Mol. Wt. 434.997 

 {A basic dye; absorption maxima about 589, [54-5.5]) 

 Solubility at 26°C: in water 3.12%; in alcohol 3.66% 



