26 MANUAL OF MICROBIOLOGICAL METHODS 



Casares-Gil Flagella Stain^ 

 As Published by Plimmer and Paine {1921) 



Mordant : 



Tannic acid 10 g 



AlCl3-6HoO 18 g 



ZnCh 10 g 



Basic fuchsin^ 1-5 g 



Alcohol (60 %) 40 ml 



The solids are dissolved in the alcohol by trituration in a mortar, adding 10 ml of the 

 alcohol first, and the rest slowly. This alcoholic solution may be kept several years. 

 For use, mix with an equal quantity of water (Thatcher, 1926) or dilute with 4 parts 

 of water (Casares-Gil), filter off precipitate, and collect filtrate on the slide. 



Staining schedule: 



1. Prepare smears of young cultures, on scrupulously cleaned slides as 

 above directed. 



2. Filter mordant onto slide as above directed (preferably using Thatch- 

 er's 1 : 1 dilution) ; allow to act for 60 sec without heating. 



3. Wash in tap water. 



4. Flood slide with freshly filtered Ziehl's carbol fuchsin (page 13), and 

 allow to stand 5 min without heating. 



5. Wash with tap water. 



6. Air-dry, and examine. Sometimes considerable search may be needed 

 before finding a satisfactorily stained part of the smear. 



Results: Fagella well stained (red) in the case of those bacteria (e.g., 

 colon-typhoid group, aerobic sporeformers) that do not have extremely 

 delicate flagella. 



Gray\s Flagella Stain 

 Gray {1926) 



Mordant: Solution A 



KA1(S04)2-12H20 (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) 



HgCh (sat aqu solution) 2 ml 



Solution B 



Basic fuchsin (sat ale solution) 0.4 ml 



Mix solutions A and B less than 24 hr 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. 



1 See Galli-yalerio (1915). 



- The authors specify rosanilin hydrochloride. There are, however, other basic 

 fuchsins more universally available which ought to prove equally satisfactory. 



