SECTION TWO 



6. Counterstain in Borrel's Blue (diluted as above: Solution 

 D) for one or two minutes. 



7. Rinse in distilled water ; drain and carefully blot away excess 

 water. 



8. Dehydrate and differentiate the Borrel Blue, controlling by 

 examination under the microscope. 



9. Clear in xylol and mount. 



Results: ' 



T.B. or leprosy, bright red; other bacteria, blue; cells and cell 

 debris, varying shades of blue ; cell nuclei, blue. 



N.B, : For demonstrating leprosy, differentiation of the carbol 

 fuchsin (stages 4 and 5) must be very carefully carried out, as this 

 organism is more easily completely decolorized than T.B. 



CARBOL FUCHSIN - HAEMATOXYLIN 

 For tubercle bacilli in mammalian tissue 



Solutions required: 



A. Alum Haematoxylin : 



Potash alum . . . . . . 20 gm. 



Haematoxylin . . . . . . i gm. 



Thymol . . . . . . . . i gm. 



Distilled water . . . . . . 400 ml. 



B. Carbol fuchsin (Ziehl Neelsen) i volume 

 Distilled water . . . . • • 3 volumes 



Technique: 



Tissues are fixed in Zenker or Flemming and embedded in 

 paraffin wax, L.V.N, or Celloidin. 



1. Paraffin sections are brought down to distilled water; then 

 stained one to five minutes in Solution A. 



2. Differentiate if necessary with acid alcohol, controlling under 

 the microscope, till nuclear detail is sharp and clearly defined; 

 wash thoroughly in water. 



F 81 



