
Name Lab Section
Aseptic Technique - Observations and Results – 5 points
1. Why do you disinfect your work area at the beginning of lab and then again at the end of lab? Answer thoroughly!
(1 pt)
2. If you have used proper aseptic technique to inoculate a new test tube of nutrient broth from a
pure culture of Bacillus subtilis, how many types of bacteria do you expect to grow in the new broth?
And why? (1.5 pts)
True or False questions:
3. Disinfectants kill vegetative cells, viruses and endospores. (0.5 pt)
4. _________ Flaming the top of the test tube sterilizes the top of the tube lowering the risk of contamination
of the culture. (0.5 pt)
5. It is acceptable to set the test tube caps on the lab bench when doing a bacterial transfer from
one tube to another if you have disinfected your lab bench. (0.5 pt)
6. When transferring bacteria from a solid media using an inoculating loop you should be able
to see the bacteria on the loop, if not you don’t have enough. (0.5 pt)
7. _________ The laboratory instrument used to transfer the bacteria to the agar plate to create a streak
plate is called an inoculating wand. (0.5 pt)
At the start of the lab, you do this to kill any microorganisms that may be present at the time.
At the end of the lab, you do this to ensure microorganisms that were potentially left behind
are killed off. Vegentative cells and viruses are killed off; but endospores are not with brief
disinfectant
One type of bacteria should be grown; Bacillus subtillus. This is only when proper aseptic
technique is performed. If theres a variety of basteria grown, improper aseptic technique was
performed.