SECTION TWO 



processes appear purple or reddish. Nuclei and nucleoli are well 

 differentiated. 



Reference: Spoerri, Rosette (1948), Stain Tech., 23, 133-5. 



DAHLIA ACETIC (Ehrlich) 

 For mast cell granules in sections 



Solution required: 



Distilled water . . . . . . 100 ml. 



Absolute alcohol . . . . . . 50 ml. 



Glacial acetic acid . . . . 12-5 ml. 



Dahlia . . . . . . . . 10 gm. 



Dissolve by heating in a flask, lightly plugged with cotton-wool, 

 on a water bath. Allow to cool ; then filter. 



Technique: 



1. Fix tissues in absolute alcohol and embed in Celloidin. 



2. Immerse sections in the staining solution for twelve hours. 



3. Differentiate in 95% alcohol. 



4. Clear in origanum oil and mount in balsam or in cristalite. 



Results: 



Granules of mast cells are stained reddish violet. 



DOPA REAGENT 



For melanoblasts * 



Solutions required: 



A. Dopa reagent (3 : 4-dihydroxy- 



phenylalanin) . . . . 0-2 gm. 



Cold distilled water . . . . 200 ml. 



Note: This solution,^ which deteriorates fairly 

 rapidly at normal temperatures, should be kept in a 

 refrigerator. When the solution turns dark red it is 

 useless and should be discarded. 



B. Buffer tablet pH 7-4 . . . . i tablet 

 Distilled water (cold) . . . . 100 ml. 



95 



