34 



MANUAL OF MICROBIOLOGICAL METHODS 

 Table 1. Dye Solubilities at 26°C {Continued) 



* These figures are grams per hundred grams of saturated solution (the others being 

 grams per hundred milliliters). 



t The color acids of these dyes (not listed here) are practically insoluble in water. 



Note: These figures are ordinarily for recrystallized dyes. Commercial samples 

 are generally less soluble often by as much as 30 per cent. 



Source: Based on data obtained at the Color Laboratory of the U. S. Department of 

 Agriculture. See Conn (1953), pp. 289-290. 



Staining schedule: 



1. Smear a bit of tissue on a slide. 



2. Dry in the air, and fix with gentle heat. 



3. Pour the above staining fluid onto the slide through a coarse filter 

 paper. Allow to stand 4 min. 



4. Rinse very rapidly with 0.5 per cent aqueous citric acid. 



5. Wash quickly and thoroughly with tap water. 



6. Counterstain about 10 sec with 1 per cent aqueous methylene blue. 



7. Rinse in tap water. 



8. Dry, and examine. 



Results: Rickettsiae, red; cell nuclei, deep blue; cytoplasm, light blue. 



REFERENCES 



Albert, Henry. 1920. Diphtheria bacillus stains with a description of a "new" 



one. Am. J. Public Health, 10, 334-337. 

 . 1921. Modification of stain for diphtheria bacilli. J. Am. Med. Assoc, 



76, 240. 



