Neutral Stains 249 



of basic fuchsin and picric acid) being especially well known as a 

 tissue stain. 



The Pappenheim panoptic triacid stain is a modification of 

 Ehrlich's triacid compound. In this combination methylene blue 

 or methylene azure is substituted for methyl green. It is a tissue 

 stain of use in certain special technics. Another well-known 

 neutral stain is the Twort (1924a and b) formula in which neutral 

 red and light green are combined. The Twort stain is valuable 

 for staining animal parasites and other animal organisms in tissues. 

 Maurer and Lewis (1922) (see page 165) have combined safranin 

 in a neutral stain with some acid violet and have employed the 

 compound dye in staining glandular tissue. 



Ehrlich proposed various other neutral stains, the best known 

 being a compound of acid fuchsin and methylene blue used 

 for staining blood; and a compound of narcein, an acid dye, with 

 two basic dyes pyronin and methyl green or methylene blue. A 

 combination of orange G with a gentian violet has been proposed 

 by Bensley (1911) as a stain for the A and B cells in the islands of 

 Langerhans. 



