MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



CARBOL FUCHSIN - BRILLIANT YELLOW 

 For tubercle bacilla in sputum smears 



Solutions required: 



A. Carbol fuchsin (Ziehl Neelsen). 



B. Brilliant yellow i% aqueous . . 15 ml. 

 Sulphuric acid 25% . . . . 40 ml. 



Distilled water . . . . . . 30 ml. 



Absolute alcohol . . . . 10 ml. 



Technique: 



1 . Fix sputum smears on a horizontal surface over boiling water 



2. Stain with carbol fuchsin solution for three to five minutes, 

 heating over a small bunsen flame in the usual manner, until steam 

 rises. 



3. Pour off excess stain. 



4. Allow the slide to cool somewhat before rinsing the prepar- 

 ation thoroughly with distilled water. 



5. Counterstain and differentiate for one half to one minute 

 with the brilliant yellow solution. 



6. Wash well with distilled water. 



7. Drain; blot thoroughly, and examine. 



Results: 



Tubercle bacilli are stained red against a clear yellow back- 

 ground. 



CASTANEDA'S STAIN 

 For Rickettsiae and elementary bodies 



Solutions required: 



A. Phosphate buffer solution pH 7-5 . . 20 ml. 



Formalin (Formaldehyde 40%) . . i ml. 

 Methylene blue 1% in absolute 



methyl of ethyl alcohol . . . . 0-15 ml. 



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