Name: Kim G.
Status: Educator
Age: 30s
Location: N/A
Country: N/A
Date: September 2004
Question:
I am trying to do an experiment for the first time with
bacteria. I have just plain agar. I had already poured plates and had
students in my first class take their fingerprints and swabs of their
desks, etc. I have an incubator that I have set at 37 degrees Celsius.
During my planning period, I kept researching bacteria and I realized I
had not added a nutrient to the agar. I read a simple recipe that called
for a cube of beef bouillon.
I did not have that, but the cafeteria had
chicken noodle soup that day so I filtered about 50 ml and added it to a
new batch of agar. I poured new plates and again I had my last period
class get samples and incubate at 37 degrees. It has been 24 hours and I
do not see any growth on the plates. Is it still too early? When should I
see optimal growth.
Replies:
I would give it a couple of days. After filtration, there may not be enough nutrients
in the chicken noodle soup and there may be too much NaCl. There probably needs to be
some simple sugars in the nutrient agar like glucose.
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