6o4 LABORATORY HINTS 



LABORATORY HINTS. 



THE EXAMINATION OF THE BLOOD. 



To Clean Slides. 



Slides should be of the medium, not the best, quality for the 

 tropics. 



Boil in strong soda Avater for five minutes. 

 Wash well in running water. 

 Place in 50 per cent. ILSOj fur ti\e minutes. 

 Wash thoroughly to remove all acid. 

 Drain and place in methylated spirit. 



To Clean Cover Slips. 



These should be of the best quality. 



Boil for ten minutes in bichromate soluiion with a low flame. 



Wash well and remove all traces of yellow colour. 



Drain and place in methylated spirit. 



CHOICE OF STAINS. 



Basic stains do well for newly growing cells, but more mature and 

 permanent ones as red cells take acid stains better. 



Hematoxylin and eosin are good in the tropics and do not fade. 



Leishman's stain is better at first but fades later. 



Hematoxylin should be matured in (|ua1ily by light and air. 



Leave the bottle in the sun with the cork loose. 



To stain for blood changes, use hematoxylin and eosin, but use 

 Leishman's for unfixed blood films. 



To stain for bacteria, use Loefifler's methylene blue or carbol 

 fuchsin (dilute, four minutes). 



To stain for animal and vegetable parasites, use carbol thionin or 

 carbol fuchsin. 



Another film must be used for the acid-fast test. 



To stain for tissue changes in sections, use hematoxylin two and 

 a half minutes, eosin ten .seconds. 



If for protozoal parasites use : — 



Hematoxylin, fifteen minutes, acid alcohol ten seconds, or 

 Carbol thionin or 

 \^an Gieson stain. 



