A student observes a researcher streaking a plate numerous times, flaming the loop between streaks. The researcher is likely using the ___________ method to isolate microorganisms.

Verified step by step guidance

1. Understand the context: The researcher is streaking a plate multiple times and flaming the loop between streaks, which is a common technique in microbiology to isolate individual colonies of microorganisms.
2. Recall common isolation methods: The main methods to isolate microorganisms on agar plates include the streak plate method, spread plate method, and pour plate method.
3. Identify the method based on the description: Flaming the loop between streaks and streaking the plate multiple times is characteristic of the streak plate method, which dilutes the sample across the surface to obtain isolated colonies.
4. Explain the purpose of flaming the loop: Flaming sterilizes the loop to prevent carrying too many microorganisms from one section to the next, ensuring progressive dilution.
5. Conclude that the method described is the streak plate method, used to isolate pure cultures by spreading microorganisms over the agar surface in a pattern that thins out the sample.

Key Concepts

Streak Plate Method

The streak plate method is a microbiological technique used to isolate pure bacterial colonies by spreading a loopful of culture over the surface of an agar plate in a pattern that thins out the sample. This dilution across the plate allows individual cells to grow into separate colonies.

Flaming the Loop

Flaming the loop involves sterilizing the inoculating loop by passing it through a flame before each streak. This prevents cross-contamination and ensures that fewer bacteria are transferred in subsequent streaks, aiding in the isolation of single colonies.

Isolation of Microorganisms

Isolation is the process of separating a single type of microorganism from a mixed culture to obtain pure colonies. This is essential for studying specific microbial characteristics and for accurate identification and analysis.