SECTION TWO 



LEISHMAN STAIN 

 For blood, malaria parasites, trypanosomes, etc., in smears 



This stain offers a simple and precise method of staining blood 

 for diagnostic purposes. 



Best results are obtained by buffering the distilled water to pH 

 6-6-7-0. 



Technique for blood films : 



Fixation is unnecessary unless the films are to be kept in stock 

 for any length of time, in which case they should be fixed for five 

 minutes in pure methyl alcohol at room temperature. 



Thin film method : 



1. Air-dried films are stained, without fixing, for one minute 

 with five to ten drops of the stain; then double the quantity of 

 distilled water (i.e. ten to twenty drops) is added and mixed by 

 rocking the slide gently. 



2. Allow this diluted stain to act for five to ten minutes; then 

 pour off. 



3. Wash gently with distilled water; then differentiate by 

 flooding the slide with distilled water and allowing the water to 

 remain on the slide for about one half to one minute, until the 

 film appears pink to the naked eye. 



4. Pour off; blot gently and dry in air. 



Results: 



Similar to Wright's stain. 



Thick film method : 



This method should be employed in searching for blood para- 

 sites when negative results have been obtained by the thin film 

 method. 



I. A film is prepared by spreading three to five drops of blood 

 in a circle about 15 mm. diameter over a slide; then without 

 fixation, it is allowed to dry at room temperature from twelve to 

 twenty-four hours, protected from dust. The time required for 



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