Which of the following is a common method for obtaining cells to initiate a microbial cell culture?

• A. Incubating the culture medium without any inoculum
• B. Inoculating the culture medium with a sample from a pure colony
• C. Sterilizing the culture medium with autoclaving
• D. Adding antibiotics to the culture medium

Answer: (B)

Verified step by step guidance

1. Understand the goal: To initiate a microbial cell culture, you need to introduce living microbial cells into a sterile culture medium so they can grow and multiply.
2. Evaluate each option: - Incubating the culture medium without any inoculum means no cells are added, so no growth will occur. - Sterilizing the culture medium with autoclaving is a preparation step to kill any existing microbes, not a method to obtain cells. - Adding antibiotics to the culture medium is used to inhibit unwanted microbes, not to obtain cells.
3. Focus on the option 'Inoculating the culture medium with a sample from a pure colony': This involves transferring cells from a single, isolated colony (which contains genetically identical cells) into fresh medium to start a new culture.
4. Recognize that inoculating from a pure colony ensures the culture starts with a known, uncontaminated population of microbes, which is essential for reproducible and accurate microbiological experiments.
5. Conclude that the common method for obtaining cells to initiate a microbial culture is to inoculate the sterile culture medium with a sample taken from a pure colony.