184 Silver Impregnation I (chap. 14) 



5. W'ash in running water: 5 minutes. 



6. Bleach in oxalic acid 5% (5 gm./lOO ml. water): 2 minutes or 

 until sections are clear. 



7. Wash in running water: 5-10 minutes. 



8. Treat with ferric chloride solution: 2 minutes. 



9. Wash in running water: 3 minutes. 



10. Wash in distilled water, 2 changes. 



1 1. Impregnate in ammoniacal silver hydroxide solution: ?> miniUes. 



12. Rinse briefly in distilled water. 



13. Reduce in formalin, 10%: 2 minutes. 



14. Wash in running water: 3 minutes. 



15. Tone in gold chloride: few seconds or tmtil color has turned to 

 purplish grey. 



16. Rinse briefly in distilled water. 



17. Fix in sodium thiosulfate, 5% (5 gm./lOO ml. water): 3 minutes. 



18. Wash in rinininw water: 5 minutes. 



19. Counterstain if desired. 



20. Dehydrate, clear, and mount. 



results: 



reticulum — black 



other tissue elements — depends on coimterstain 



comments: 



Lillie warns that hematoxylin counterstaining may not offer enough 

 contrast with reticulum, because presence of ferric chloride inakes the 

 hematoxylin take black. 



Wilder's Method (1935) 

 fixation: any good general fixative. 



solutions: 



Phosphomolybdic acid, 10%: 



phosphomolybdic acid 10.0 gm. 



distilled water 100.0 ml. 



Uranium nitrate: 



uranium nitrate 1 .0 gm. 



distilled water 100. ml. 



Ammoniacal silver nitrate: 



Add ammonia (28% reagent), drop by drop to 5 ml. of 10% silver 



nitrate (10 gm./lOO ml. water) until precipitate which forms is almost 



