120 Biological Stains 



k20 CELESTIN blue B C. I. NO. 90O 



Synonym: Coreine 2R. 



CONH2 



I 

 C2H5 /\_N=/\ 



\ I I II 



N~\/~0=\/~OH 



/ i I 



C2H5 CI OH 



C17H18N3O4CI; MoL Wt. 363.795 

 {Absorption maxima about 654-5 [GOO]) 



Preferred by Proescher and Arkush (1928) to either gallocyanin 

 or gallamin blue as a nuclear stain. As in the case of these two 

 other dyes, the iron lake, prepared by boiling 2-3 minutes in a 5% 

 aqueous solution of ferric ammonium sulfate, is employed for the 

 staining solution. Lendrum and McFarlane (1940) recommend 

 this dye in a modification of the Mallory connective tissue stain. 



k25 LACMOID C. I. NO. 908 



Synonyms: Resorcin blue. Iris blue. Fluorescent blue. 



There is some confusion as to the actual chemical structure of 

 this dye. It is recorded differently in different sources; and there 

 is little question but that it varies according to the manufacturer 

 from which it is obtained. At least one product of American 

 manufacturer is believed to have the following structure: 



II II 



NaO-\/\ /\/=0 



O 



This does not agree with the Colour Index, under the number 

 above cited, where a formula is given in which the NaO- radical 

 is replaced by NH4O-, and where a brominated derivative is re- 

 garded as properly called resorcin blue but not lacmoid. 



Lacmoid has been used for its indicator properties. This dye, 

 apparently, was employed by Tsvett (1911) under the name of 

 resorcin blue, as a histochemical reagent for the detection of 

 callose. Nebel more recently (1931) combined it with martins 

 yellow (a dye at present unobtainable commercially) in a stain for 

 pollen tubes. 



