Another way of plating organisms, next to streaking, on agar plates is the spot analysis. This type of analysis is often used to check the viability of cells and performed with pinners (often also called froggers). A third used technique is the use of sterile glass beads to plate out cells. In this technique cells are grown in a liquid culture of which a small volume is pipetted on the agar plate and then spread out with the beads. Replica plating is another technique in order to plate out cells on agar plates. These four techniques are the most common, but others are also possible. It is crucial to work in a sterile manner in order to prevent contamination on the agar plates. Plating is thus often done in a laminar flow cabinet or on the working bench next to a bunsen burner.