Inoculating Loops

Inoculating loops are used to transfer microorganisms to growth media or for staining slides. They are an important part of the sterile technique as their use permits transfer only of the material of interest.

Nichrome wire loop

  • Nichrome wire: The Rolls-Royce of inoculating loops (shown above). The nichrome-wire loop resists deterioration with repeated heat/cooling cycles needed to sterilize the loop before each use. Most scientific supply houses sell nichrome-wire loops for a few dollars each. Often the metal based has a threaded screw on one end to which a loop can be attached (shown in bottom half of the image).
  • Disposable plastic loops: One use only. Come pre-packaged and sterilized, ready for use.
  • Sterile wooden sticks: Can purchase already sterilized, or place in containers of choice and sterilize before use.

Sterilized toothpicks: Toothpicks from the store can be sealed in aluminum foil and sterilized. Use each toothpick only once to transfer or streak microbial material onto agar plates. The toothpicks are frequently too short to be used to inoculate broth cultures.

Related information: Sterilizing an inoculating loop and Streaking Agar Plates

Microbiology Techniques