STAINING, PRACTICAL AND THEORETICAL 



Chromophore : 



OXAZINE GROUP 



+ 



c— o=c 



C— N=C 



\ 



About twelve dyes of this group are used in microtechnique. 

 One is an acid, two are amphoteric, and the rest are basic dyes. 

 Examples of oxazine dyes are given below : 



BRILLIANT CRESYL BLUE 



Michrome No. 404. Molecular weight 318. A basic dye, pH 2-2*. 

 Solubility at 1^° C: water 3%, absolute alcohol 2%. 



(H5C2)2N 



H3C 



=NH9 



+ 



ci- 



CELESTIN BLUE 



Michrome No. 66. Molecular weight 364. A basic dye, />// 2-6*. 

 Solubility at 15° C: water 2%, absolute alcohol 1*5%. 



^ CO . NH2 



(H5C2)2N 



OH 



+ 



ci- 



* 1% in neutral distilled water; see pages 17 and 29. 



60 



