A vortex mixer is a simple laboratory device used for the rapid mixing of samples in test tubes, well plates, or flasks. The vortex mixers have variable speed settings from 100 to 3000 rpm. This mechanism is used to homogenize a sample, resuspend a solution, or promote reactions within the tube. The vortexer consists of an electric motor with a rubber cup. This rubber cup oscillates in a circular motion when the motor is turned on. When you press a test tube into the rubber cup, the motion of the rubber cup is transmitted to the tube, and this causes the liquid in the tube to create a vortex.