SECTION TWO 



2. Stain for fifteen to forty-five minutes in a mixture consisting 

 of one part of Giemsa stain and twenty-five parts of distilled water. 



3. Wash in distilled water; blot and dry in air. 



Results: 



Nuclei of the leucocytes are stained reddish purple, while the 

 rest of the leucocytes appear similar to Leishman-stained prepar- 

 ations. Cytoplasm of plasmodia: blue. Chromatin: red. 



Thick film method (for demonstrating malaria parasites); 



1. A film is prepared by spreading 3 to 5 drops of blood in a 

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

 it is allowed to dry on a level surface for eighteen to twenty-four 

 hours at room temperature protected from dust ; or for two to three 

 hours in an incubator at 37° C. 



2. Stain for forty minutes in a mixture consisting of one part of 

 Giemsa stain and fifty parts of distilled water. 



3. Wash for five to ten minutes in distilled water; blot and dry 

 in air. 



Results: 



Malaria parasites : chromatin, clear red ; cytoplasm, clear blue. 



Treponema pallidum. 



Solutions required: 



A. Giemsa stain. 



B. Sodium carbonate, A.R. 1% in 

 distilled water. 



Technique: 



1. A lesion is rubbed roughly, until it bleeds, with a swab which 

 has been damped with absolute alcohol. 



2. While bleeding is taking place, swab the chancre at intervals. 

 After a few minutes a clear fluid exudate will appear from the 

 abraded surfaces. 



3. A drop of the clear fluid exudate (free from blood) is taken 

 from the periphery of the lesion with a platinum wire loop, trans- 

 ferred to a scrupulously clean slide, and spread into a film. 



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