19'2 Biological Stains 



r20 mercurochrome ixo 



This is a proprietary name applied to a fluorescein derivative 

 closely related to eosin: dibromo-hydroxy-mercuri-fluorescein. 



Br Br 



NaO I 



\/V_o_ 





J 



C2oH806HgBr2Na2; Mol. Wt. 750.700 



The dye has been widely advertised as a disinfectant especially 

 for the skin; and there has been considerable discussion in the 

 literature as to its actual value for the purpose. It has staining 

 properties not unlike an erythrosin, or phloxine. Baldwin (1928) 

 states that it may be used in 2% aqueous solution in place of eosin, 

 especially for blood woxk and for tissues after Zenker fixation; 

 thus employed it is more intense than eosin and has a stronger 

 affinity for cytoplasmic structures. Detwiler and McKennon 

 (1929) employ it in concentration of from 1 :500,000 to 1:1,000,000 

 as a fungicidal agent for the treatment of amphibian embryos. 

 Conklin (1934) recommends it as a counterstain to malachite green 

 in the Wirtz spore stain for bacteria. 



R25 ERYTHROSIN, YELLOWISH C. I. NO. 77I 



Synonyms: Erythrosin R or G. Pyrosin J. Dianthine G. lod- 



eosin G. 



This is a fluorescein in which there are two substituent iodine 

 atoms instead of four bromine atoms as in yellowish eosin. 



I I 



NaO I I 



0_/\ O 



c= 



COONa 



C2oH805l2Na2; Mol. Wt. 628.09S 

 {An acid dye; absorption maximum about 510.5) 



