SECTION SEVEN 



2. Add an equal volume of distilled water, rock the slide to mix; 



then allow the diluted stain to act for one minute. 



3. Pour off; blot and dry in air. 



Results: 



Bacteria are stained dark blue; capsules, light blue. Mucus, 

 red. 



LUGOL'S IODINE - EOSIN 



For dififerentiating between spores and vegetative forms in 



bacterial smears 



Solutions required: 



A. Lugol's iodine . . . . . . 40 ml. 



Eosin yellowish . . . . . . 2 gm. 



Phenol cryst. . . . . . . 2 gm. 



B. Methylene blue 1% aqueous . . 10 ml. 

 Absolute alcohol . . • • 5 ml* 

 Distilled water . . . . • • 85 ml. 



Dissolve by shaking thoroughly in a conical flask ; 

 filter before use. 



Technique: 



1. Fix smears by flaming in the usual manner. 



2. Place slides, smear upwards, on the corner of a tripod; flood 

 with the iodine-eosin stain (Solution A) and heat the underside 

 of the slide for five minutes, with a small flame, until the liquid 

 begins to boil. 



3. Remove the flame momentarily, applying it again the instant 

 the liquid ceases to boil ; repeat this process two or three times. 



4. Pour off excess stain ; allow the slide to cool somewhat ; then 

 plunge quickly into distilled water. - 



5. Stain for two minutes in the methylene blue solution. 



6. Rinse with distilled water. 



7. Drain; blot dry; examine. 



Results: 



Spores, deep pink. Vegetative form, blue. 



379 



