STAINING, PRACTICAL AND THEORETICAL 



3. Stain in a freshly prepared, unfiltered, saturated solution of 

 Chlorazol Black in 70% alcohol for five to ten minutes. 



4. Drain off excess dye ; dehydrate ; clear in xylol and mount. 



Results: 



Embryo, epithelial cell tissues : outlined in black. Chromatin : 

 black. Nuclei: black. Muscle fibres: intense black. Lympho- 

 cytes: intense black. Blood cells: yellowish green. Cytoplasm: 

 greenish grey. 



Kidney and intestine : varying shades of green, grey and black. 

 Blood cells : light green. 



Nuclei and chromosomes are stained black; cytoplasm and 

 secreted products grey ; chitin, green ; glycogen, red. 



Notes: 



(a) Benzyl alcohol may also be used as a solvent, in which case 

 results are somewhat different. 



(b) If it is desired to differentiate chlorazal black, dilute 

 " Milton " (a proprietary antiseptic) may be used for the purpose. 



(c) The stain may be incorporated with Lactophenol. 



(d) In an earlier paper (Cannon, 1937) terpineol was suggested 

 in error as the differentiating agent. 



Reference: Cannon, H. G. (1941). 



CHLORAZOL FAST PINK 



As an in vivo stain for unmineralized bone and tooth 

 matrix in experimental animals 



Solution required: 

 Chlorazol fast pink 5% in physiological saline. 



Technique: 



1. Two adult litter-mate rabbits (A and B) were intravenously 

 injected with 10 ml. of the above solution. 



2. Ten days after injection, fluorine was administered to rabbit B 

 to induce the lesions of skeletal fluorosis. 



168 



