228 Biological Stains 



This compound is seldom called for in biological work but has 

 been used by Broda (1939), mixed with azo blue and Titan yellow, 

 as an histochemical reagent for magnesium. 



El3 CARYCINEL RED 



O 



_NH.C5Hu 



O 



C19H19NO2; Mol. Wt. 293.350 

 El 4 COCCINEL RED 



O 



II _NH-C5Hu 



CsHn.NH O 



C24H30N2O2; Mol. Wt. 378.496 



These are two oil-soluble dyes first described and named by 

 Lillie (1945b). He regarded them, together with the following 

 dye (Oil blue NA) as good fat stains when employed in the super- 

 saturated isopropanol technic (Lillie, 1945 a). Coccinel red stains 

 fat scarlet, carycinel red a deep crimson. 



El5 OIL BLUE NA 



Probably of the following chemical formula: 



O NHCbHu 



O NH.CsHii 



C24H30N2O2; Mol. Wt. 378.496 

 {Absorption maxima about \595], 64-0.) 



This dye has come into prominence since 1940, as a stain for 

 rubber in plant sections. Whittenberger (1944) thus employs it 

 without a counterstain, while Addicott (1944) suggests either 

 safranin or Congo red for counterstaining. According to Lillie 

 (1945 a) it may also be used for staining fat in animal tissue. 



For use in staining fat in tissue, see Staining Procedures, p. ID3-2O. 



