20 METHODS OF EXAMINATION 



blotting paper and dry in the air. A more intense staining is 

 secured if 1% potassium carbonate solution is added in the propor- 

 tion of 1 or 2 drops to 10 cc. of distilled water before the stain is 

 mixed with it. 



Giemsa's stain is excellent for protozoa, but is not so good for 

 the blood corpuscles. 



Pappenheim's modification of May-Giemsa's method. Two 

 staining mixtures are needed each of which may be purchased 

 ready prepared. They are May-Grunwald's eosin — methylene 

 blue disssolved in methyl alcohol and Giemsa's stain (new formula). 

 The Giemsa's stain must be diluted just before use in the propor- 

 tion of 15 drops of the stain to 10 cc. of distilled water. 



The air dried film is covered with the May-Grunwald stain 

 which is allowed to act for 3 minutes. An equal number of drops 

 of distilled water is then added to the stain and allowed to act one 

 minute. The fluid is then poured off and, without washing, the 

 freshly prepared Giemsa solution added. This is allowed to act 

 for 15 minutes when the preparation is thoroughly washed, then 

 dried, not over a flame. Pappenheim regards this method as su- 

 perior to any other now in use and states that it is the only one 

 he now uses. 



Graham's alphanaphthol-pyronin method. The smear is al- 

 lowed to dry thoroughly in the air. It is fixed one or two minutes 

 in a freshly prepared mixture of nine parts ninety-five per cent. 

 alcohol and one part formalin. 



Wash in water and flood with the following alphanaphthol 

 solution, which keeps well so far as its staining powers are con- 

 cerned. 



Alphanaphthol (Merck's " Recrystallized " or "Reagent"). . 1 gm. 



Alcohol, 40% 100 cc. 



Hydrogen peroxide .2 cc. 



Allow it to act four or five minutes. Wash and place in a dish 

 of running water for about fifteen minutes. 

 Stain two minutes with the following solution: 



Pyronin .1 gm. 



Anilin 4 cc. 



Alcohol, 40% % cc 



Dissolve the pyronin in the alcohol and add the anilin. This 

 solution keeps well. 



