Question

After using an inoculating loop or needle to transfer a culture from one medium to the next, what step should be taken next to avoid contamination?

1) Flame the loop or needle
2) Place the loop or needle in a disinfectant solution
3) Wipe the loop or needle with a sterile cloth
4) Leave the loop or needle as it is

Answer 1

To avoid contamination after transferring a culture, the inoculating loop or needle should be flamed to sterilize it, then cooled before use.

Step-by-step explanation:

After using an inoculating loop or needle to transfer a culture from one medium to the next, to avoid contamination the next step should be to flame the loop or needle. This sterilization process involves heating the metal tool in a flame until it is red hot, which kills any remaining microorganisms. Once the loop or needle has been heated, it is important to let it cool before using it to inoculate a new medium. To cool the loop, briefly touch it to the sterile agar away from any colonies. This process is critical in maintaining an aseptic work environment and ensuring that cultures do not become contaminated with other microorganisms.