LESSON III 



Bacterial Colouring Matters Bacillus Pyocyaneus Bacillus 

 Prodigiosus. 



Separation of Bacterial Colouring Matters (Gessard, 

 Andrewes, Fordos) 



(a) Bacillus pyocyaneus (Klein-Andrewes). 



(1) Inoculate twenty agar-agar tubes (streak cultures) 

 from an actively chromogenic culture, and keep them at 22 

 to 30 C. 



(2) When the agar-agar has become dark green, add to 

 each tube 5 to 8 cc. of pure chloroform, break up the agar- 

 agar with a glass rod, arid shake each tube vigorously, till 

 all the blue pigment is dissolved out by the chloroform. 



(3) Collect the chloroform extracts in a small flask, and 

 filter through filter-paper moistened with chloroform. 



A clear blue solution of pyocyanine is thus obtained, 

 which may be concentrated by slow evaporation 

 in the dark at 38'5 0. 



Reactions 

 (1) Evaporate a little of the chloroform solution in a 



