MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



Results: 



Trypanosomes and leucocytes are seen as motile, bright, green 

 luminous bodies while the erythrocytes are scarcely visible and 

 are non-fluorescent. 



8. Staining of Trypanosomes in Dried Blood Films 



Solution required: 



Auramine O o-i % aqueous . . lOO ml. 

 Phenol crystals . . . . • • 5 gm. 



Technique: 



1. Fix air-dried blood films, suspected of containing trypano- 

 somes, in pure methyl alcohol for two to five minutes, then wash 

 with distilled water. 



2. Stain for about four minutes in the auramine solution then 

 wash with distilled water for one to two minutes, keeping the slide 

 in the dark. 



Results: 



Examined with blue light fluorescence microscope, erythrocytes 

 appear as dark green, slightly luminous circles, while trypano- 

 somes shine with a bright golden fluorescence against a black back- 

 ground. By covering the film with a drop of liquid paraffin and a 

 coverglass the contrast will be even more marked. 



9. Staining of Tubercle Bacilli 



Solutions required: 



A. Auramine O aqueous 0-1% ., 100 ml. 

 Phenol crystals . . . . • • 5 gm. 



Dissolve by shaking. Do not apply heat as aura- 

 mine decomposes at 40° C. 



B. Methylene blue 0-1% aqueous. 



C. Potassium permanganate 0'i% aqueous. 



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