Silver hnpregnation for Reticulum 181 



14. Coiinterstain (if desired) in hematoxylin and picro-ponceau (van 

 Gieson), page 165. 



15. Dehydrate, clear, and mount. 



results: 



reticulum — black 



collagen — red to rose 



nuclei — black, blue or brownish 



cytoplasm — greyish yellow 



muscle fibers, elastin — light yellow 



comments: 



To prevent loosening of sections, Mallory (1938) substitiued an 

 alcoholic for the aqueous silver sohuion of the original method. See 

 also German (1939). 



Gridley's Method (1951) 

 fixation: any good general fixative. 



solution: 



Ammoniacal silver hydroxide: 



To 20.0 ml. of 5% silver nitrate add 20 drops of 10% sodium hy- 

 droxide. Add fresh 28% (reagent) ammonia drop by drop until pre- 

 cipitate which forms is almost redissolved. Add distilled water up to 

 60.0 ml. 



procedure: 



1. Deparaffinize and hydrate slides to water. Remove HgCl. if 

 present. 



2. Treat with 0.5% periodic acid (0.5 gm./lOO ml. water): 15 

 minutes. 



3. Rinse in distilled water. 



4. Treat with 2% silver nitrate (2 gm./lOO ml. water): 30 minutes, 

 room temperature. 



5. Rinse in 2 changes of distilled water. 



6. Impregnate in ammoniacal silver solution: 15 minutes, room 

 temperature. 



7. Rinse rapidly in distilled water. 



8. Reduce in 30% formalin (30 ml./70 ml. water): 3 minutes. Agi- 

 tate gently. 



9. Rinse in 3 or 4 changes of distilled water. 



10. Tone in gold chloride (10 ml. 1% stock solution/40 ml. u-ater) 

 until yellow brown color has changed to lavender-grey. 



