STAINING METHODS IV46-17 



colon-typhoid group, aerobic sporc-formcrs) that do not have 

 extremely delicate flagclla. 



gray's flagella stain 

 Gray (1926) 



Mordant: Solution A 



KAl (804)2' 121120 (sat. aqu. solution) 5 ml. 



Tannic acid {'■20% aqu. solution) 2 ml. 



(A few drops of chloroform must be added to this if a large quantity is 

 made up) 



HgCls (sat. aqu. solution) 2 ml. 



Solution B 



Basic fuchsin (sat. ale. solution) 0.4 ml. 



Mix Solutions A and B less than twenty-four hours before using. Both solutions 

 separately may be kept indefinitely, but deteriorate rapidly after mixing. 



Staining schedule: 



1. Prepare smears from young cultures as above directed. 



2. Flood slide with freshly filtered mordant and allow to act 8-10 



min. 



3. Wash with a gentle stream of distilled water, and follow steps 



4-6 of above schedule (Casares-Gil's method). 

 Results: Same as with Casares-Gil method. 



leifson's stain 

 Leifson (1930) 



KA1(S04)2.12H20, or NH4A1(S04)2.12H20 (sat. aqu. solution) 20 ml. 



Tannic acid (20% aqu. solution) 10 ml. 



Distilled water 10 ml. 



Ethyl alcohol, 95% 15 ml. 



Basic fuchsin (sat. solution in 95% ethyl alcohol) 3 ml. 



Mix ingredients in order named. Keep in tightly stoppered bottle and the stain 

 may be good for a week. 



Staining schedule: 



1. Prepare slides as for the preceding methods. 



2. Flood slides with the above solution and allow to stand 10 min. 



at room temperature in warm weather, or in an incubator in 

 cold weather. 



3. Wash with tap water. (If a counterstain is desired, borax 



methylene blue may be applied, without heat, followed 

 by another washing. See p. IV46-19). 



4. Dry and examine. 



Results: When no counterstain is used, same as with the two above 

 procedures; with methyelne blue counterstain, see under "Capsule 

 Stains", below. 



BAILEY METHOD 



Bailey (1929) 



MODIFIED BY FISHER AND CONN (1942) 



This method is specially recommended for bacteria on which 

 flagella are difficult to stain (as is frequently the case with soil and 



