Bacteria Staiiiing 315 



7. Dehydrate, isopropyl alcohol, 99%, 2 changes: 3-5 minutes in 

 each. 



8. Clear and mount. 



results: 



acid-fast bacteria — red 

 nuclei — blue 



Ziehl-Neelsen (putt's modification, 1951) 

 fixation: general fixative, but 10% formalin best. 



solutions: 

 New fuchsin: 



new fuchsin, C.I. 42520 (magenta III) 1.0 gm. 



phenol (carbolic acid) 5.0 gm. 



ethyl or methyl alcohol (absolute) 10.0 ml. 



distilled water to make 100.0 ml. 



Acetic alcohol: 



glacial acetic acid 5.0 ml. 



absolute ethyl alcohol 95.0 ml. 



Counterstain: 



methylene blue chloride, C.I. 52015 0.5 gin. 



absolute ethyl alcohol 100.0 ml. 



procedure: 



1. Deparafhnize and hydrate slides to water; remove HgCl2. 



2. Stain in new fuchsin, room temperature: 3 minutes. 



3. Treat with lithium carbonate, saturated aqueous: 1 minute. Agi- 

 tate gently, discard solution if it becomes blue. 



4. Differentiate until pale pink in acetic alcohol. 



5. Rinse in absoliue alcohol, 2 changes: 1-2 minutes in each. 



6. Counterstain. 



7. Decolorize in absolute alcohol, 2 changes: ^ minute each. 



8. Clear and moiuit. 



results: 



acid-fast bacteria — red 

 red blood corpuscles — pink 

 mast cell granules — deep blue 

 other bacteria — blue 

 nuclei — blue 



