The stirring and mixing devices commonly found in laboratories include stirring motors, magnetic stirrers, shakers, small pumps for fluids, and rotary evaporators for solvent removal. At a laboratory scale, mixing is achieved by magnetic stirrers. Magnetic stir bars are radial-flow mixers that induce solid body rotation in the fluid being mixed. A variety of stir bar configurations exist, but because of the small size and (typically) low viscosity of the fluid, it is possible to use one configuration for nearly all mixing tasks. The cylindrical stir bar can be used for suspension of solids, as seen in iodometry, DE agglomeration (useful for preparation of microbiology growth medium from powders), and liquid–liquid blending.