Title:
Reproducing Pasteur’s Experiment
By Colby Geisinger and Noah Butsack
Purpose:
The purpose of the experiment is to prove or disprove spontaneous generation by recreating Louis
Pasteur’s experiment.
Drawing:
Procedure:
Step 3: A length of glass tubing was given by the teacher. Then safety goggles were put on and sleeves
were pulled up. The Bunsen burner was ignited by turning on the gas and lighting it with a striker. After
that, adjustments were made to get the best possible flame. The glass was held with two fingers making
sure not to keep the fingers on the end of the glass tube. Then the glass was held over the flame where
the bends were to be made. The glass was able to be bent once the area being heated had turned into
an orange flame. When the flame on the glass became orange then the glass was slowly bent into a
curve. Then the glass was taken away from the fire to be cooled. The glass was then ready to be bent
again once the glass had cooled off a bit. Once the glass was bent into an S-Curve the glass was put in
through a rubber stopper on one end. After that the glass and stopper were wrapped all the way around
in aluminum foil. A piece of tape with the team name was then put onto the foil so that it could be
recognized. Once this is complete and the glass and stopper are wrapped in foil they are ready to be put
in the autoclave.
Step 4: All of the materials that were used and needed to be sterilized were wrapped in aluminum foil.
Once they were covered they were put in an autoclave at 250 ̊F and at 20psi for 18 to 20 minutes. After
that amount of time and in those conditions all of the materials will be sterilized.
Table:
Day
Open Beaker
Open Flask
Straight
tube Flask
S-tube
Flask
Closed
Flask
1
Little sediment
Little sediment
Clear
A lot of
sediment
clear
3
Little sediment
Little sediment
Clear
A lot of
sediment
Tiny sediment
5
Darker color,
brothy film
Darker color,
little more
sediment
Darker color,
more little
sediment
A lot of
sediment
Tiny sediment
7
Darker color,
brothy film,
more sediment
Darker color,
more sediment
Little sediment
A lot of
sediment
Tiny sediment
9
Dry, dirty, no
signs of liquid
More little
sediment
Little sediment
A lot of
sediment
Tiny sediment
11
Dried up
More
sediment
More
sediment
A lot of
sediment
Tiny sediment
Additional Observations: There was a lot of sediment in the S-tube flask. However, the S-tube flask did
not gain any sediment throughout the experiment. The tiny sediments in the closed flask were not
noticed until day 3 but it did not gain any sediment throughout the experiment.
Sources of Error: The only errors were that the S-tube Flask had a lot of sediment in it because when the
hay infusion was poured into the flask it was the last of the hay infusion so all of the sediments at the
bottom of the infusion got into the S-tube Flask and the tiny sediments in the closed flask were not
noticed on the first day.
Analysis and Conclusions:
1. Based on your observations in this investigation, explain why surgical operating rooms are
kept sterile?
Surgical Operating rooms are kept sterile because otherwise organisms and bacteria from the air
or from other people could get inside someone else’s body and contaminate them which could
cause that person to become ill.
2. When a doctor takes a throat culture for the diagnosis of throat problems, must sterile
techniques be used when obtaining the sample? Explain.
Yes, sterile techniques must be used when obtaining the sample otherwise the person taking
the sample could get the same bacteria that someone’s throat had.
3. Did the results of your experiment prove or disprove spontaneous generation?
The results of the experiment proved spontaneous generation.
4. Did your experiment produce the same results as Pasteur’s experiments?
Yes, the experiment produced the same results as Pasteur’s experiments.
5. Would Pasteur be able to use your data and observations to prove or disprove spontaneous
generation?
Even though some of the hay got into the S-tube Flask Pasteur would still be able to use the data
and observations to prove spontaneous generation.