Myelin 217 



results: 



myelin sheaths — black 

 background — light yellow 



Mahon Method (1937) S 



fixation: 10% formalin. Cut paraffin sections 15-20 microns. Not good 

 for frozen sections. 



embedding: paraffin method. 



solutions: 

 Mordant: 



ferric ammonium sulfate (ferric alum) 4.0 gm. 



distilled water 100.0 ml. 



Hematoxylin: 



lithium carbonate solution (to 93 ml. distilled 

 water add 7 ml. of saturated aqueous lithium 

 carbonate 90.0 ml. 



hematoxylin solution (1 gm./lO ml. absolute al- 

 cohol 10.0 ml. 



Mix immediately before use. 



procedure: 



1 . Deparaffinize and hydrate slides to water. 



2. Mordant: 15-30 minutes. 



3. Rinse in 2 changes distilled water: 1 minute. 



4. Stain in hematoxylin: 30-60 mintites. 



5. Wash in riuinino water: 2 minutes. 



6. Treat with lithium carbonate, 7% (7 gm./lOO ml. water) until 

 myelin is dark blue and background is colorless: 15-30 ininutes. 

 Watch carefully that too much dye is not extracted; also, pro- 

 longed exposure to lithinin carbonate may loosen sections. 



7. Wash thoroughly in running water: at least 5 minutes. 



8. Dehydrate, clear, and mount. 



results: 



myelin — dark blue 

 background — colorless 



