196 



Biological Stains 



Chamberlain (1932, page 69; 1927), mentions having used it 

 successfully in place of magdala red in staining algae. His original 

 technic called for magdala red ; but true magdala red does not serve 

 his purposes. Inasmuch as erythrosin (see above) was evidently 

 sold in the past as magdala red and Chamberlain can duplicate his 

 original results with phloxine, the chances are that some of the 

 magdala red formerly available was either phloxine or else that 

 phloxine and erythrosin give similar results by Dr. Chamberlain's 

 technic. 



About 1920 Dr. F. B. Mallory, like many others, found it 

 difficult to obtain an eosin of either domestic or foreign origin 

 which would give consistently reliable results by his eosin-methy- 

 lene blue method described in 1904. After testing out, on the 

 advice of a member of the Commission, a series of eosins and 

 closely related dyes he wrote that phloxine is "the best eosin I 

 have yet found for use in the eosin-methylene blue stain for paraffin 

 sections of tissues fixed in Zenker's fluid."* Here again is a case 

 where phloxine apparently was obtained before the war under an 

 incorrect name and the incorrect name used in the publication of a 

 well-known technic. 



For technic of Mallory's phloxine-methylene-blue stain, see Staining Pro- 

 cedures, pp. IA4-2O; IIIB3-4. 



For use as counterstain in Gram-Weigert technic for bacteria in tissues, see Id. 

 p. IIIB3-8. 



r35 



C. I. NO. 777 



ROSE BENGAL G 



Synonym: Rose SA, 

 Various shades denoted: Rose bengal Ny AT, NTy NTOy and B. 



NaO 



0-/V=0 



CI 



c= 



I 



I I I 



COONa 



-CI 



C2oH405l4Cl2Na2; Mol Wt. 948.820 

 {An acid dye) 



This particular rose bengal apparently has not been employed 

 by biologists. The dye of that name sold by stain companies at 

 present is the following. 



*Quoted from personal letter. 



