Laboratory Centrifuges. A centrifuge is a laboratory device that is used for the separation of fluids, gas or liquid, based on density.Separation is achieved by spinning a vessel containing material at high speed; the centrifugal force pushes heavier materials to the outside of the vessel.aboratory Centrifuges. A centrifuge is a laboratory device that is used for the separation of fluids, gas or liquid, based on density.