Pure cultures of safe (non-pathogenic) bacteria can be used for laboratory investigations.
What cultures need to grow and to keep the culture pure what must you do?
Thanks.
To grow a pure culture of bacteria in a laboratory, you will need the following:
1. Culture media: This refers to a nutrient-rich substance on which the bacteria will grow. There are different types of culture media available, such as agar plates, broth, or slants, which provide the necessary nutrients for bacterial growth.
2. Inoculum: The inoculum is the sample or source from which you collect the bacteria you want to culture. It can be obtained from various sources, like a pure culture, a clinical sample, or an environmental sample.
3. Sterile technique: To maintain the purity of the culture, you need to follow sterile techniques throughout the process. This involves using sterile equipment (such as pipettes and petri dishes), working in a clean and isolated area (such as a laminar flow hood), and taking precautions to avoid contamination.
To keep the culture pure, you should perform the following steps:
1. Streak plate technique: Start by streaking the bacteria onto an agar plate using a sterile inoculating loop. This technique involves diluting the sample across the surface of the agar in a pattern to obtain isolated colonies. Each isolated colony represents a single bacterium.
2. Subculturing: To prevent overcrowding and maintain the purity of the culture, it is necessary to regularly transfer a small amount of the pure culture to a fresh culture medium. This process is called subculturing and can be done by streaking isolated colonies from one plate onto a new plate or by inoculating broth with a small amount of the pure culture.
3. Slant or stab cultures: For long-term storage, you can maintain pure cultures by using slant or stab cultures. These are solid media in test tubes that provide a vertical growth surface for bacterial inoculation. The inoculated tubes are then sealed and stored in a cool environment, like a refrigerator or freezer.
By following these steps and practicing good aseptic technique, it is possible to grow and maintain pure cultures of bacteria in the laboratory for various research and investigative purposes.