It consists of an electric motor with the drive shaft oriented vertically and attached to a cupped rubber piece mounted slightly off-center.

When a test tube or other appropriate container is pressed into the rubber cup (or touched to its edge) the motion is transmitted to the liquid inside and a vortex is created.

The vortex mixer was invented by brothers Jack A. and Harold D. Kraft while working for Scientific Industries, Inc., N.Y.,(a laboratory apparatus manufacturer).

The technique is better suited to accelerate the mixture of solutions which do not require the kinetic energy input needed to create suspensions.

For incubating applications, vortex mixers can employ precision temperature control at various mixing speeds which make them ideal for a wide variety of molecular biology applications including immunochemical reactions, enzyme and protein analysis, and microarray analysis.