216 Silver Impregnation II (chap. 15) 



solutions: 



Mordant, modified Marchi fluid: 



potassium dichromate 25.0 gm. 



sodium sulfate 1 .0 gm. 



distilled water 100.0 ml. 



Add 1 ml. of above to: 



ferric alum, 5% aqueous (3 gm./60 ml. water) 60.0 ml. 



Hematoxylin: 



hematoxylin 1.0 gm. 



absolute ethyl alcohol 10.0 ml. 



Dissolve hematoxylin in alcohol and add: 



distilled water 90.0 ml. 



lithium carbonate, saturated ac|'ieoiis 4.0 ml. 



Mix thoroughly. Prepare fresh each time. 



Differentiating solution: 



potassium permanganate 0.5 gm. 



distilled water 100.0 ml. 



Thin celloidin: 



gum mastic, saturated in absolute alcohol 2.0 ml. 



celloidin or nitrocellulose, 10% 7.0 ml. 



ether, anhydrous 45.0 ml. 



absolute ethyl alcohol 45.0 ml. 



acetone 10.0 ml. 



procedure: 



1. Deparaffinize and run slides into absolute alcohol: 2 minutes. 



2. Dip twice in thin celloidin, blot lightly with filter paper and 

 harden in 95% and 80% alcohol: 2 minutes each. 



3. Hydrate down to water. 



4. Mordant, 60° C: 30 minutes. 



5. Preheat hematoxylin, 60°C, add slides, stain: 30 minutes. 



6. Wash in running water until sections blue: 2 minutes. 



7. Differentiate with potassium permanganate until myelin fibers 

 are jet black and background is light yellow: maximum 30 sec- 

 onds. 



8. Wash in running water: 2 minutes. 



9. Dehydrate, clear, and mount. 



