668 TECHNIQUE 



3. Wash well and differentiate in water; the effect may be 

 varied by the duration of the washing (ten to forty minutes). 



4. Dehydrate in alcohol, clear, and mount. 



When a sharper nuclear dye is desired the stain may be used as 

 a counter-stain after hematein. In this case the methyl blue solu- 

 tion should be allowed to act only three to five minutes. The 

 methyl blue used in this method is a cytoplasmic dye and should 

 not be confounded with methylen blue. 

 Triacid Stain (Ehrlich) : 



Saturated aqueous solution of orange G 13 cc. 



Saturated aqueous solution of acid fuchsin. . 7 cc. 



Distilled water 15 cc. 



95 per cent, alcohol 15 cc. 



Saturated aqueous solution of methyl green. 12.5 cc. 



95 per cent, alcohol 10 cc. 



Glycerin 10 cc. 



Be certain that the solutions of the dyes are saturated, and mix 

 in the order given. 



The following formula by Mayer may be substituted: 



Distilled water 45 cc. 



Glycerin 10 cc. 



95 per cent, alcohol 25 cc. 



Acid fuchsin 3 grm. 



Orange G 2 grm. 



Methyl green 1 grm. 



Mix the fluids and dissolve the dyes in the order given. 

 When used for staining sections, either of these formulas should 

 be diluted with five to ten volumes of the following mixture : 



Glycerin 10 cc. 



Distilled water 15 cc. 



95 per cent, alcohol 25 cc. 



1. Stain five to ten minutes in the diluted solution. (Use full 

 strength for blood smears.) 



2. Rinse in water. 



3. Dehydrate in absolute alcohol. (Smears are dried in the air.) 



4. Clear and mount. 



MOUNTING 



After staining, the sections are opaque ; they must be rendered 

 transparent for microscopical examination. This is accomplished 

 by permeating the sections with oil ; but since oil and water are 



