What was the purpose of using a lit Bunsen burner during the experiment?

Using a lit Bunsen burner during the experiment primarily serves to create an up-draught, which helps limit aerial contamination. When the burner is lit, the heat produced creates a current of rising air. This motion of air can help prevent airborne microbes and particles from settling on sterile surfaces and materials in the vicinity, thereby maintaining a contamination-free working environment. This is particularly important in microbiological experiments, where the presence of contaminants can significantly affect the results.

While a Bunsen burner can also contribute to sterilization processes in the laboratory, its most direct and immediate benefit during an experiment involving sensitive materials is the up-draught that reduces the risk of contamination. Thus, understanding the role of the Bunsen burner in creating a controlled environment is essential for effective laboratory practices.