DSOO 



DYE STAIN'S OF GENEHAL APPLlfATION 



2G9 



13.2 



13.3 



13.4 



13.5 



13.6 

 13.7 



13.31 

 13.32 



Techniques employing thiazine.s, and their eosinates, in combination 

 with other dyes. 



13.21 In combination with orange (j 



13.22 In combination with other dyes 



Techniques employing methyl green as the nuclear stain 



13.30 Typical example 



Staining a section of the suprarenal body in the methyl green- 

 acid fuchsin-orangc (i stain of Foley 193',) 

 In comI)ination with pyronin 

 In combination with other dyes 



Techniques employing acid fuchsin as the nuclear stain 



13.40 Tj'pical examples 



Preparation of a transverse section of Amphioxus using the acid 

 fuchsin-aniline blue-orange Ci stain of Mallory 1901 

 Involving the acid fuchsin-phosphomolybdic reaction 

 Involving the acid fuchsin-phosphotungstic reaction 

 Not involving either reaction. 



Techniques employing safranin as the nucl(;ar stain 



13.50 Typical example 



13.51 Other techniques 



Techniques employing hematoxylin as the nuclear stain 

 Other complex techniques of general application 



13.41 

 13.42 

 13.43 



DS 00 Generalities 



DS 00 GENERAL OBSERVATIONS 



The term dye staining as used in the 

 present work applies to those methods by 

 which objects or parts of objects are 

 colored. It is distinguished from metal 

 staining (Chapter 23) more by convention 

 than by any scientific actuality, for some 

 of the methods emi)loyed involve tlie ap- 

 plication of salts of metals for the produc- 

 tion of color, while some of the metal- 

 staining techniques involve the deposition 

 of colored compounds in the same manner. 



The terms dye, pigment, stain, and lake 

 have become so hopelessly- confused in 

 biological literature as almost to have lost 

 their original meaning. Technically a stain 

 (and the process of staining) involves only 

 the arldition of color to an othei'wise color- 

 less material. The term dye should be aj)- 

 ])lied to those stains which remain on the 

 material on which the}^ are deposited and 

 cannot subsequently be removed by nor- 

 mal techniques. A pigment, as tlie term is 

 customarily used in other than biological 

 literature, I'cfers to a solid color matter 

 not in a state of solution. But the use of 

 the term dye for ruthenium I'ed is widely 

 current in biological literature even 

 though the material itself is a finely di- 

 vided suspension of an insf)luble material. 

 A lake, in nonbiological literature, is an 



insoluble compound of a dye and some 

 other material, usually a metal, which is 

 used to hold it in place upon the dyed 

 material. Though still technically cor- 

 rectly emploj^ed with regard to the mor- 

 dant staining with hematoxylin, carmine, 

 and the like, the term should also be ap- 

 l)lied to many othei- methods of staining, 

 such as the eosin-azur stains. 



The necessitj^ for staining specimens in- 

 tended for microscopical examination is 

 not nearly as great as the widespread use 

 of the process would lead one to supi)ose. 

 Many writers have stressed the un(le.'?ir- 

 ability of the current habit of staining 

 every object which is to be examined 

 under the microscoi)e, and one cannot do 

 better in this respect than quote the words 

 (in the writer's translation) of Langeron 

 1942, 485: "Histological science has cer- 

 tainly not progressed in pioportion to the 

 enoruKHis luunber of staining reagents 

 which liave been placed at its disposal. 

 One cannot too often repeat that staining 

 is not the whole of histology and that the 

 first duty of the microtoinist is not to be a 

 dyer but to know how to study through a 

 microscope. That is the art which the 

 former inastei's jjossessod fundamentally 

 and which it would l)e desirai)le to see a 

 little better cultivated today." It would 



