Inoculation loops are simple tools to retrieve an inoculum from a culture of microorganisms to transfer to another broth or a culture plate. They utilize a small loop with a diameter of about 5 mm at the tip, which may be made of plastic, platinum, tungsten or nichrome. 

Inoculation loops use surface tension phenomenon to remove a consistent amount of the liquid suspended inoculum for reliable results. The loop is then used in the cultivation of microbes on culture plates by transferring inoculum for streaking.

Plastic loops are provided in sterile packaging and are for single use, while metal inoculation loops are sterilized with flame or infrared heat source before and after each use.  This allows metal tools to be reused in different experiments without cross-contamination.