Streaking is a technique used to isolate a pure strain of microorganisms, often bacteria, from a sample containing multiple strains. A wire loop is dipped into the sample and used to streak bacteria in successive passes on an agar plate, diluting the concentration with each pass so that isolated colonies can grow from single bacteria. The plate is then incubated, allowing each colony to multiply from a single parent bacterium. This process isolates pure strains that can be identified, studied, or tested.