26 PRACTICAL BACTERIOLOGY 



XXIII. METHODS FOR STAINING CILIA OR 

 FLAGELLA. 



LoFFLEiTs METHOD, MODIFIED BY GUNTHER. 



1. Take a young culture grown on the surface of agar-agar media, 

 and make a hanging-drop specimen, examine it under the microscope, 

 and note if the bacteria are motile. 



2. Put a drop of distilled water on a clean cover-glass with a 

 sterile platinum loop, inoculate the drop with a little of the culture 

 material, and spread gently over the surface of the cover-glass. 



3. Allow the specimen to air dry, and then pass three times 

 through the flame, but be careful not to heat too much. 



4 Filter a few drops of Loffler's mordant (see 62) on the cover- 

 glass, and allow it to remain one-half to one minute. (Heat is un- 

 necessary, as it only yields dirty, unsatisfactory specimens.) 



5. Remove the mordant with a fine stream of water from the 

 wash-bottle, and dry the cover-glass in the ordinary manner by 

 blowing, etc. 



6. Filter a drop of anilin water fuchsin solution on the surface 

 of the cover-glass, or without filtering place a drop of fresh watery 

 alcoholic solution of fuchsin on the cover-glass with a pipette, and 

 heat the cover-glass over the flame until steam arises, remove, and 

 allow the warm stain to remain one minute on the cover-glass, then 

 wash off with water. 



7. Dry quickly, and mount in xylol balsam. 



The addition of acids or alkali to the mordant are now no longer 

 considered necessary, and Giinther considers heating the mordant 

 unnecessary. 



XXIV. BOWHILUS METHOD OF STAINING FLAGELLA 

 AND BACTERIA SIMULTANEOUSLY WITH ORCEIN. 



1. A small quantity of material is taken from the surface of a young 

 agar-agar culture (previously tested by ' the Hanging Drop '), and a 

 suspension made in boiled distilled water in a test-tube. 



2. Leave the tube undisturbed for five minutes, then place one drop 

 of the bacteria-suspension on a clean cover-glass, and air dry. 



3. Fix in the flame, holding the specimen between the fingers to 

 prevent excessive heating. 



4. Pour some orcein solution (see Stains, 59) in a watch glass, 

 float the cover-glass, preparation side downwards, on the surface of 



