MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



4. Dehydrate with 95% alcohol. 



5. Clear in origanum oil. 



6. Mount in Canada balsm or in Cristalite. 



Results: 



Mast cell granules are stained red ; nuclei, blue. 



METHYLENE BLUE POLYCHROME - GLYCERINE 



ETHER (Unna) 



For differentiating mast cells and plasma cells 



Solutions required: 



A. Formalin (40% formaldehyde) . . 50 ml. 

 Absolute alcohol . . . . 100 ml. 



B. Polychrome methylene blue (Unna) 



C. Glycerine ether (Unna) . . • • 5 nil- 

 Distilled water . . . . . . 35 ml. 



Technique: 



1. Fix tissues in Solution A; dehydrate; clear; embed in 

 paraffin wax. 



2. Immerse sections in the methylene blue solution for ten 

 minutes. 



3. Rinse in distilled water. 



4. Differentiate in the glycerine ether mixture from one half to 

 one minute until the sections appear to be deep sky blue to the 

 naked eye (care should be taken that the sections are not over- 

 differentiated). 



5. Wash thoroughly in distilled water for a few minutes. 



6. Fix sections to slides and carefully blot with filter paper. 



7. Dehydrate rapidly with absolute alcohol. 



8. Clear in xylol and mount. 



Results: 



Nuclei are stained blue, while mast cells are red and plasma are 

 blue. 



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