NUCLEAR STAINS. 37 



5 minutes, rinsed thoroughly in Distilled Water" , then differen- 

 tiated in 90 p. c. Alcohol, dehydrated, cleared and mounted in 

 Balsam. 



The above solution, to which 1 p. c. of Glacial Acetic Acid 

 has been added, is employed for fixing and staining nuclei 

 in fresh vegetable tissues. 



Methyl Green has been used for obtaining the peculiar pink 

 reaction with amyloid tissue, but this is probably due to the 

 fact that most methyl-greens contain methyl violet, as an 

 impurity. Methyl green free from violet does not give the 

 reaction. 



(ii.a] Ekrlich-Biondi Fluid. 



This is usually given as follows : Saturated Aqueous 

 Solution of Methyl Green, 5 cc. ; Saturated Aqueous Solution 

 of Orange, 10 cc. ; Saturated Aqueous Solution of Acid 

 Fuchsine, 2 cc. ; for use dilute with about 40 volumes of 

 Water. 



As these concentrated solutions form a precipitate when mixed, it is 

 better to dilute each of them with 20 to 40 volumes of water before 

 mixing 1 . 



The solution is conveniently made as follows: Methyl Green, 0-5 

 grm. ; Distilled "Water, 100 cc. : Acid Fuchsine, 0'5 grm. ; Distilled 

 Water, 40 cc. : Orange, 2 grms. ; Distilled "Water, 200 cc. Mix the 

 solutions and filter before use. 



In some cases (serial sections for instance) it is convenient to use all 

 the dyes in one solution, but in other cases it is better to stain the nuclei 

 with Methyl G-reen and counter-stain with Rubin and Orange. 



Sections are usually placed in this stain for 12 hours, then washed, 

 dehydrated, cleared and mounted. 



This triple stain has also been strongly recommended as a counterstain 

 to Hsematoxylin, but in that case the Methyl Green is not required 

 Rubin and Orange (p. 42) answers equally well, if not better. 



(ii.J) Iodine Green. 



This is another name for Methyl Green. Formerly Methyl 

 Iodide was employed in the manufacture of this green, and 



