186 Silver Impregnation I (chap. 14) 



quired by some reticulum methods. Lillie {1946) disagrees that 

 uranium nitrate is a sensitizer; claims it is an oxidizer. 



Reticulum, Collagen, and Elastin. (humason and lushbaugh 1960) 

 FIXATION : any good general fixative. 



solutions: 



Ammoniacal silver carbonate: 



To 10 ml. of 10.27o silver nitrate (1.2 gm./lOO ml. water) add am- 

 monia (28% reagent) drop by drop until the precipitate, which forms, 

 is almost dissolved. Add 10 ml. of 3.1% sodium carbonate (3.1 

 gm./lOO ml. water) and distilled water to make 100 ml. Filter. 



Buffered formalin: 



formalin, 5% 50.0 ml. 



sodium carbonate, 1% (1 gm./IOO ml. water) . . 1.0 ml. 



Orcein solution: 



orcein 0.5 gm. 



707o ethyl alcohol 100.0 ml. 



hydrochloric acid, concentrated 0.6-1.0 ml. 



Aniline blue solution: 



aniline blue WS, C.I. 42780 0.1 gm. 



oxalic acid 2.0 gm. 



phosphomolybdic acid 15.0 gm. 



distilled water 300.0 ml. 



procedure: 



1. Deparaffinize and rinse off xylene in absolute alcohol. 



2. Pyridine-glycerol (2:1), room temperature: overnight, or 15% 

 aqueous pyridine: 15 minutes. 



3. Treat with 95% alcohol: 3 minutes. 



4. Wash in running water: 5 minutes. Remove HgCl2 if present. 



5. Treat with periodic acid, 0.5% (0.5 gm./IOO ml. water): 15 

 minutes. 



6. Wash in running water: 5 minutes; rinse in distilled water. 



7. Impregnate with ammoniacal silver carbonate solution, 37°C: 

 1.5-2.0 hours. 



8. Rinse in ammoniated distilled water (1 drop ammonia/ 100 ml. 

 water) a few seconds to remove excess silver precipitates. Rinse 

 in distilled water. 



9. Reduce in buffered formalin: 5 minutes. Use fresh solution. 



