inoculation loop inoculation loop an inoculation loop (also called a smear loop, inoculation wand or microstreaker) is a simple tool used mainly by microbiologists to pick up and transfer a small sample of microorganisms called inoculum from a microbial culture, e.g. for streaking on a culture plate. this process is called inoculation. inoculation loops the tool consists of a thin handle with a loop about 5 mm wide or smaller at the end. it was originally made of twisted metal wire (such as platinum, tungsten or nichrome), but disposable molded plastic versions are now common.