SECTION SEVEN 



5. Stain for two minutes with Breed's stain, prepared as above. 



6. Wash quickly in 90-95% alcohol until the intense blue colour 

 changes to a faint tinge. 



7. Dry and examine. 



Results: 



Bacteria are stained dark blue against a lighter blue background 



BRILLIANT CRESYL BLUE 

 For reticulated cells and platelets 



Solutions required: 



A. Brilliant Cresyl Blue 0-3% in pure 



absolute ethyl alcohol. 



B. Leishman stain or Wright's stain. 



Technique: 



1. Place a drop of 0-3% Brilliant Cresyl Blue stain in absolute 

 alcohol on a slide and allow it to dry. 



2. A drop of blood 2 to 3 mm. in diameter is placed on another 

 slide and brought in contact with the dried stain; the two slides 

 are then manipulated hinge-like until all the stain has gone into 

 solution and the blood appears blue-black. Allow the slides to 

 come into contact to spread the drop ; then separate the slides and 

 allow the films to dry. 



3. Counterstain with Leishman or Wright by the standard 

 technique. 



Results : 



Reticulum of immature red cells is stained clear cut blue; 

 backgroiind, pale blue (fresh), or pink. Blood platelets, pale blue 

 or lilac. 



Note: The counterstain may be omitted if it is desired only to 

 count the platelets. 



The number of red cells per cm. should be determined separ- 

 ately in a haemocytometer, and the ratio of platelets to red cells 

 computed from the stained preparation. 



351 



