Streaking (microbiology)

In microbiology, streaking is a mechanical technique used to isolate a pure strain from a single species of microorganism, often bacteria. Samples from a colony derived from a single cell are taken from the streaked plate to create a genetically identical microbiological culture grown on a new plate so that the organism can be identified, studied, or tested. Different patterns can be used to streak a plate. All involve the dilution of bacteria by systematically streaking them over the exterior of the agar in a Petri dish to obtain isolated colonies which contain gradually fewer numbers of cells. If the agar surface grows microorganisms which are all genetically same, the culture is then considered as a pure microbiological culture.