Question

What should always be done prior to transfer of a bacteria from a broth?

Answer 1

Before transferring bacteria from a broth, one must sterilize all equipment, use a flame-sterilized inoculating loop, and ensure the initial clarity of the culture to avoid contamination.

Step-by-step explanation:

Before the transfer of a bacteria from a broth, it is critical to practice aseptic techniques to avoid contamination of the culture and to ensure the safety of the person conducting the experiment. This begins with the sterilization of all equipment and supplies, including inoculating instruments such as loops and needles, and pipettes for liquid transfer.

One must use a flame-sterilized inoculating loop or sterile pipette to transfer bacteria. After picking up a colony or part of a colony with the sterilized instrument, it is transferred to the new broth in a tube. Moreover, when working with the broth culture, it is important to observe its initial clarity to confirm that there is no pre-existing contamination, which would compromise the experiment's results. After transfer, incubation occurs under specific conditions prescribed by the experiment protocol.

Answer 2

Prior to transferring bacteria from a broth, it is important to use aseptic technique and sterilize all equipment. Flame-sterilization of inoculating loops or needles is common practice, and the broth should be checked for clarity to rule out pre-existing contamination.

Step-by-step explanation:

Transfer of Bacteria from Broth Culture

When transferring bacteria from a broth, it is crucial to maintain aseptic technique to avoid contamination. Prior to the transfer, ensure that all equipment and supplies, including loops, needles, and pipettes, are sterilized.

This can typically be done by flame-sterilizing the inoculating instruments. Additionally, observe the broth culture for clarity to ascertain that there is no pre-existing cloudiness before inoculation, which could indicate contamination. After confirming the sterility of the equipment and clarity of the broth, use a sterilized inoculating loop to pick up a single colony or part of a large colony from a streak plate culture or mixed culture broth. This colony is then carefully transferred into fresh broth or spread onto an agar plate for further culturing, followed by incubating at the specified temperature.

As part of the procedure, work near a flame to ensure a sterile work environment, cap the tubes properly after transfer, mix the contents fully, and carefully label each tube to distinguish between subcultures and the sterility control.

Always practice techniques under the guidance of an experienced instructor or a set of standardized laboratory protocols to reduce the risk of introducing contaminants into the culture.