Abstract: A device for the removal of liquid samples from a liquid receptacle comprises a sample container with a piston which subdivides the container into a first chamber receiving a liquid sample and a second chamber receiving a piston driving medium. The device further includes a dosing device for the piston driving medium, which is connectable to the sample container by a plug-in coupling which can be locked at both sides thereof.

Abstract: A process for the pure preparation of particles, biological cell systems, colloids and the like, in which liquid density gradients are produced in a rotating centrifuge container (1), and in which the particles and the like are introduced into the centrifuge container (1), individual bands being produced in such a manner that the bands containing the heavier particles are more remote from the axis of rotation than are the bands containing the lighter particles. The density gradients are constructed by the introduction of fractions of different density (a-f) via a cannula (18) which extends into the centrifuge container (1) to just before a tip (19) of the latter, the lightest fraction (a) being introduced first and the heaviest fraction (f) being introduced last.