MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



SILVER NITRATE - GOLD CHLORIDE - PARACARMINE 



(Da Fano) 



For Golgi apparatus 



A. Cobalt nitrate i% aqueous . . lOO ml. 

 Formalin . . . . . . • • 15 ml- 



B. Silver nitrate 1*5% aqueous. 



(N.B. : This should be stored in an amber or blue 

 glass bottle.) 



C. Cajal's Reducer. 



Hydroquinone 2% aqueous . . 100 ml. 

 Neutral formalin . . . . . . 15 ml. 



Sodium sulphite anhydrous . . 0-5 gm. 



N.B.: This solution should be freshly prepared. 



D. Gold chloride 0-2% aqueous. 



E. Sodium thiosulphate 5% aqueous. 



F. Paracarmine (Mayer). 



* 

 Technique: 



1. Pieces of tissue no thicker than 3 mm. are fixed from two to 

 eighteen hours in the cobalt nitrate formalin solution, according 

 to the size and nature of the material. 



2. Wash the tissue quickly in a large volume of distilled water- 



3. Immerse in the silver nitrate solution in the dark for thirty- 

 six to forty-eight hours. 



4. Wash quickly in a large volume of distilled water. 



5. Trim the tissue to a thickness not exceeding 2 mm. 



6. Immerse in Solution C (Cajal's Reducer) for two to twenty- 

 four hours in the dark. 



Note: For most soft tissues about four hours will suffice. 



7. Wash in several changes of distilled water. 



8. Dehydrate, clear and embed in paraffin wax in the usual 

 way. 



9. Cut sections up to Sju in thickness. 



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