Golgi Apparatus and Mitochondria 261 



rR(1CEDl'RE: 



1. Rinse blocks of tissue in distilled water. 



2. Impregnate in 1.5% silver nitrate (1.5 gm./lOO ml. water): 1-2 

 days. (Can use 1% for very small pieces or embryonic tissues, 2% 

 for fatty tissues and spinal cord). 



3. Rinse briefly in distilled water. 



4. Cut blocks into slices thinner than 2 mm. Reduce in developer: 

 5 hours. 



5. Wash thoroughly in distilled water. 



6. Dehydrate, infiltrate, and embed. 



7. Section, 6-7 microns, moimt and dry. 



8. Deparaffinize and hydrate to water. 



9. Tone in gold chloride: 2 hours. 



10. Rinse in distilled water and fix in 5% sodium thiosulfate: 3 min- 

 utes. 



11. Wash in running water: 5 minutes. 



12. Counterstain, if desired, in hematoxylin, thionin, carmalum, etc. 



13. Dehydrate, clear, and moimt. 



results: 



golgi — black 



cytoplasm — grey 



mitochondria — medium to dark grey or black 



comments: 



The silver preparations depend on fixation with salts of a heavy metal 

 — cobalt in DaFano's method. Aoyama (Baker, 1943) varies the 

 method using 



cadmium chloride 1.0 gm. 



formalin 15.0 ml. 



distilled water 85.0 ml. 



The rest of the procedure is the same as DaFano's. 



Direct Silver Method (elftman, 1952) 



procedure: 



1. Immerse small blocks of fresh tissue in silver nitrate, 2% (2 gm./ 

 100 ml. Avater): 2 hours. 



2. Rinse briefly in distilled water. 



3. Develop: 2 hours, in: 



h)droquinone 2.0 gm. 



formalin 15% (15 ml./85 ml. water) 100.0 ml. 



