21 
(Figs. 13 and 14) and spread the adherent organisms on the agar in the tube 
by drawing the needle once lightly over the surface of the agar from the 
bottom to the top. Be careful that the needle does not touch any other 
colony during the operation. Inoculate the other two tubes of agar from the 
respective colonies. 
4. Inoculate the broth tubes from the same colonies, rinsing the organisms 
from the needle in the broth. 
5. Leave the cultures in the incubator for 48 hours or in the locker for four 
or five days. 
6. Examine the cultures. Look for a streak along the needle track on the 
agar slopes, and for turbidity, sediment, or a surface film in the broth cultures. 
Draw and describe the cultures according to the outline for broth and agar 
streak cultures in Appendix A. 
7. Examine the organisms in each broth culture by means of the hanging 
drop and determine if they are motile. Record the morphology of the or¬ 
ganisms in each culture. 
8. (a) What are some other kinds of agar tube cultures besides slant 
cultures? 
( b ) What are the advantages of solid media for tube cultures as com¬ 
pared to liquid media. 
