Inoculating loops and needles (sometimes called microstreakers or inoculating wands) are hand-held devices for inoculating plated or tubed growth media with micro-organisms such as bacteria or yeasts prior to incubation, multiplication, and growth. The inoculum is typically streaked onto, or stabbed into, solid agar-based media, or simply introduced and dispersed into liquid media. Inoculating loops and needles are also useful for sampling and transferring small quantities of micro-organism prior to further analysis, microscopic examination, or serial dilution.

Inoculating loops and needles consist of a handle with a terminal loop or needle that is designed to pick up and transfer a small quantity of inoculum (typically 1 to 10 μL) from a donor culture to the growth medium of choice. Some loops are calibrated and color-coded to transfer semi-quantitative amounts of inoculum.