Students' Assignment:

1. Why are bile salts and sodium desoxycholate used in certain selective media?
2.  How can one identify coliforms on MacConkey’s agar?
3.  How does one differentiate Salmonella from Shigella colonies on Hektoen agar?
4.  What is the composition of mannitol salt agar? For what organism is this medium selective? What ingredient makes it selective?
5.  How is E. coli distinguished from P. vulgaris on MacConkey agar?
6.  Why can mannitol salt agar and EMB agar be described as both selective and differential media? If you carry out the differential medium experiment, comment on the differences in growth of organisms on mannitol salt agar and EMB agar.
7.  Why is mannitol salt agar used to isolate staphylococci?
8.  How can one distinguish E. coli from P. aeruginosa on
                      a.    Maconkey agar?
                      b.    EMB agar?
9.  How can one identify coliforms on MacConkey agar?
10.  How can one be able to identify pathogenic from non-pathogenic Staphylococci in MSA?
11.  What is  chocolate agar? How is it  different from blood agar?