A laboratory instrument for mixing a medium in an object carrier, wherein the laboratory instrument includes a support body, a main component for receiving the object carrier which is disposed on the support body and is movable with respect to the support body for mixing, and a mixing drive mechanism disposed on the support body, with a drive device, a first eccentric and a second eccentric, which can be driven by means of the drive device and which are configured in order to transmit a driving force produced by the drive device to the main component in order to mix the medium in the object carrier, wherein the first eccentric and the second eccentric are disposed on a peripheral edge of the support body and outside a central region of the support body.