262 Cytoplasmic Elements (chap. 18) 



4. Return to 10% formalin to complete fixation: at least overnight. 



5. Wash, dehydrate, and embed. 



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



7. Deparaffinize, clear and mount. 



results: 



Golgi — black 



comments: 



Do not use buffered formalin; it may limit the solubility of the silver 

 salts. 



If the silver is too dense, Elftman suggests bleaching it with 0.1% 

 iron alum. Check under the microscope and stop the reaction by 

 washing thoroughly in running water. 



The silver is readily oxidized, so gold toning is usually preferable 

 for a more permanent slide. This can follow deparaffinization; see 

 other Golgi methods. Also counterstaining may be included before 

 dehydrating and clearing slides. 



Elftman warns that all the black is not necessarily Golgi. 



Mitochondria Staining 



Fast Green (harmon, 1950) 

 fixation: Regaud solution (page 20). 



solutions: 

 Fast green: 



fast green FCF, C.I. 42054 4.0 gm. 



aniline 10.0 ml. 



distilled water 90.0 ml. 



Phosphomolybdic acid: 



phosphomolybdic acid 1.0 gm. 



distilled water 100.0 ml. 



Safranin: 



safranin O, C.I. 50240 1.0 gm, 



50% ethyl alcohol 100.0 ml. 



procedure: 



1. Deparaffinize and hydrate slides to water. 



2. Warm fast green solution to 62 °C just before use. Add slides, re- 

 move from heat and allow to slowly cool: 6 minutes. 



3. Rinse rapidly in distilled ^vater. 



