Using a Serial Dilution to Count Bacteria in a Sample Consider the following dilution scheme: A 1oom
Using a Serial Dilution to Count Bacteria in a Sample
Consider the following dilution scheme:
A 1oomL lake water
B 5mL lake water into 45 mL diluent 01 ml – colonies TNTC
C 1mL from B into 9ml diluent 01 ml – colonies 425
D 05mL from C into 45 mL diluent 01 ml – colonies 58
E 2mL from D into 19mL diluent 01 ml – colonies 12
F 01mL from E into 09 mL diluent 01 ml – colonies 1
a What dilution is achieved by adding 2mL of incoulum to 19mL of a diluent?
b Would you expect any change in the answer of the above problem if the firat dilution was made by adding 1 mL of sample to 9 mL of diluent? Why or why not?
c What are the total number of CFU’s in the entire 100mL amount of the original lake water sample?