STAINING, PRACTICAL AND THEORETICAL 



6. Counterstain with safranin i% aqueous, if desired, for one 

 half to two hours according to thickness of sections. 



7. Wash thoroughly in water: dehydrate; clear and mount. 



Results: 



Myelin sheaths : blue-black. Myelinated fibres : black or blue- 

 black. Grey matter: white or slightly yellow. Other structures: 

 unstained (unless a counterstain has been used). 



Note: See page 199, note [b). 



References : 



Pal, J. (1886, 1887a, 1887&, 1888). 

 Weigert, C. (1885). 



WOOL GREEN - HAEMATOXYLIN - BIEBRICH SCARLET 

 For connective tissue and muscle 



Solutions required: 



A. Picric acid, saturated in 70% alcohol. 



B. Weigert's haematoxylin A. 



C. Biebrich scarlet 1% in 1% acetic acid aqueous. 



D. Weigert's haematoxylin B. 



E. Wool Green S 1% in 1% aqueous acetic acid. 



F. Acetone and xylol, equal volumes of each. 



Technique: 



1. Immerse sections in the picric acid solution for two minutes. 



2. Wash thoroughly in running tap water. 



3. Stain for five to seven minutes in Weigert's haematoxylin A. 



4. Rinse in water and stain for three to five minutes in the 

 Ponceau S solution. 



5. Wash in water. 



6. Immerse in Weigert's haematoxylin B. 



7. Wash thoroughly in water. 



8. Stain for three to five minutes in the wool green solution. 



9. Decolorize for two minutes with 1% acetic acid. 



464 



