Question

Describe the scientific method using Pasteur’s swan-necked flask experiment as an example.

Answer 1

Pasteur recounted his famous swan-neck flask experiment, stating that “life is a germ and a germ is a life. Louis Pasteur used a flask whose neck was shaped like an S or the neck of a swan, hence the name “Swan Neck Flask.” The unique swan-neck feature of the flasks used in Pasteur’s experiment allowed air to enter the flask but prevented the entry of bacterial and fungal spores.Pasteur’s experiment consisted of two parts.

• In the first part, the broth in the flask was boiled to sterilize it. The curve of flask prevents outside air from entering the flask.When this broth was cooled, it remained free of contamination and no organism growth occurs.
• In the second part of the experiment, the flask was boiled and when the neck was broken off, bacteria reach the sterile broth and organism growth occurs.The broth in this flask became contaminated.