18 METHODS OF EXAMINATION 



balsam. Immersion oil may be removed from the film by dropping 

 on chloroform or xylene. 



With Jenner's stain the red corpuscles should have a pinkish 

 or terra cotta tint; nuclei blue; the fine granules of polymor- 

 phonuclears pinkish; eosinophile granules, deeply stained pinkish; 

 basophile granules, deeply stained dark violet. Bacteria arc well 

 stained, blue. 



Wright's stain. The staining fluid may be obtained read}' 

 for use from dealers in microscopic supplies or the dye may be 

 purchased in dry form and made up as needed. The staining fluid 

 is a solution in pure methyl alcohol of eosinate of polychrome 

 methylene blue, 0.1 gm. to 60 cc. The unfixed film, which has 

 dried in the air, is covered with the stain which is allowed to act 

 one minute. Then the same number of drops of distilled water 

 are added drop by drop. This is allowed to act two or three min- 

 utes longer when the specimen is washed with distilled water until 

 the better spread portions have a pinkish or orange tint. A few 

 seconds will usually suffice, but it may take one to three minutes. 

 The excess of water is shaken and blown vigorously from the 

 specimen which is then dried in the air. When it is dry examine 

 with the two mm. (^2 m °^ immersion objective. 



Wright's stain is an excellent one, staining the several kinds of 

 granules well. The red corpuscles should have a pinkish or terra 

 cotta tint; nuclei blue; the fine granules of polymorphonuclears 

 pinkish; eosinophile granules reddish; basophile granules a deep 

 royal purple. This stain also stains bacteria well. Wright's is pref- 

 erable to Jenner's stain for staining the protozoa found in the blood. 



Hasting's stain. The fluid, a solution of eosinate of poly- 

 chrome methylene blue in pure methyl alcohol, may be obtained 

 ready for use from dealers in microscopic supplies. The air dried 

 film, previously unfixed, is covered with the staining fluid which 

 is allowed to act one minute, then is diluted by adding a few drops 

 of distilled water until a greenish metallic scum begins to form on 

 the surface of the film. Let the diluted staining fluid act for five 

 minutes longer. Then wash in distilled water for two or three 

 seconds and dry immediately by blotting. This is an excellent 

 stain for blood, staining the various kinds of granules. The effect 

 is practically the same as is produced by Wright's stain. Hasting's 

 stain is especially good for staining the parasitic protozoa. 



