Xanthene Dyes 



179 



490 



I 



510 



I I 1 I 1 



530 550 



Tnr\/x 



570 



-1 

 590 



Fig. 23. Spectral curves of two pyronins: 

 1. Pyronin B. 2. Pyronin Y. 



It is rarely called for in biological work, but has been used by 

 Gomori (1943), mixed with methyl green, in a procedure for stain- 

 ing tissue to demonstrate deposits of calcium salts and sites of 

 phosphatase activity. 



