108 GENERAL BACTERIOLOGY 



EXERCISE 62. SEPARATION OF BACTERIAL COLORING MATTER. 



a. Make four agar streaks of Bacillus prodigiosus, which are to 

 be kept in the dark until the coloring matter is well formed. 



b. Add about 10 ce. of ether to each tube and shake vigorously 

 until the red pigment has all been dissolved out. 



c. Pour into a large test-tube and allow to stand over night in 

 the dark, then pipette off the colored portion. 



d. Divide this into four parts and treat them as foUows : 



1. Evaporate on glass slide and examine crystals formed 



under microscope. 



2. Add a few drops of hydrochloric acid, drop by drop 



3. Add a few drops of sodium hydroxide. 



4. Stand in direct sunlight. 



