SECTION SEVEN 



SUDAN BLACK B - EOSIN - METHYLENE BLUE 

 For lipoid granules in leucocytes 



Solutions required: 



A. Sudan Black B, saturated in ethy- 



lene glycol. 



Note: This should be stored in a well-stoppered 

 bottle. 



B. Eosin, yellowish i% in 70% alcohol. 



C. Methylene blue, saturated, aqueous. 



Technique: 



1. Air-dried blood films are fixed for thirty seconds in pure 

 methyl alcohol. 



2. Stain for half an hour in the sudan black solution in a stop- 

 pered staining jar. 



3. Rinse in water. 



4. Rinse thoroughly in 70% alcohol. 



5. Counterstain for thirty seconds with the eosin solution. 



6. Wash in tap water. 



7. Stain in methylene blue solution for three minutes. 



8. Rinse with distilled water. 



9. Drain and blot thoroughly ; examine under the oil-immersion 

 objective. 



Results: 



Lipoid granules are stained an intense black, whilst nuclei are 

 stained blue, and erythrocytes, red. 



SUDAN BLACK - SAFRANIN 

 For demonstrating fat in bacteria 



Solutions required: 



A. Sudan black, B saturated in 70% 



alcohol. 



B. Safranin O, aqueous 1%. 



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