STAINS AND STAINING 25 



STAIN IS USED AS FOLLOWS: 



1. Take sections of material which have been bulk stained in carmine 

 through the ordinary procedures as far as absolute alcohol. 



2. Transfer them to the staining solution for 2 minutes and rinse individu- 

 ally in absolute alcohol until sufficiently differentiated. 



3. Then transfer the slides to xylene which stops further differentiation. 

 This gives good differentiation of a large number of tissues. On embry- 

 onic material it is particularly effective, for the nuclei are red, yolk and 

 yolk granules are yellow-green to green, while yolk-free cytoplasm is 

 a clear blue. 



Complex Staining Techniques for Animal Tissues 



Complex staining solutions are those in which a series of stains, mordants, 

 and differentiating solutions are used one after another in such a manner that 

 the nuclei and all the elements of the plasma are stained in sharply contrasting 

 colors. The stains used in botany, naturally, are quite different from those used 

 in histology and pathology and are given immediately following this section. 

 Many hundred complex stains are in the literature and will be found in Gray's 

 Microtechnique, where several hundred more stains of specific application 

 are also given. Here it is intended to present only three stains which are so 

 simple to use and so excellent in their results that they should be known to 

 everyone. The first of these is: 



Mallory's Triple Stain: 

 First staining solution 



1% Acid flichsin 

 Differentiating and mordanting solution 



1% Phosphotungstic acid 

 Second staining solution 



Water 100 ml. 



Methyl blue 0.5 Gm. 



Orange G 2 Gm. 



Oxalic acid 2 Gm. 



METHOD OF USE: 



1. Accumulate sections for staining in water. 



2. Stain them in the first staining solution for 2 minutes. 



3. Rinse the slides thoroughly in water. 



4. Transfer them to the phosphotungstic acid for 2 minutes. 



5. Give the slides a very quick rinse in water. The purpose is to remove the 

 phosphotungstic acid from the slides, not from the sections. 



6. Transfer to the second staining solution for 15 minutes. 



7. Wash the slides in water until no more color comes away. 



