GB642537A - Improved method of and vessel for concentrating materials suspended in liquids - Google Patents

Abstract

<PICT:0642537/III/1> A vessel for concentrating materials suspended in liquids, e.g. by sedimentation, shaking, electrophoresis, centrifuging alone or in combination, comprises a tube of arbitrary cross-section, preferably transparent, open at both ends and tapering towards one or both ends, these openings being closed by removable stoppers or plugs, e.g. rubber or plastic, characterized by the cross-sectional area of the lower opening, where the material heavier than the liquid collects, being such that the stopper can be removed with only a determined small volume of the order of one drop, of the contents of the vessel adhering thereto while the rest of the contents remains in the vessel. A cylindrical glass tube 1 tapering towards necks 2, 3 closed by stoppers 4, 5 has indicating marks 6, 7, with or without other volume marks, to show the level for liquid or intrusion of the stopper 5 respectively. After centrifuging, the heavier concentrates are obtained by carefully withdrawing stopper 5 with drop 8 adhering thereto and lighter concentrates may be skimmed by a platinum wire loop from the upper surface of the liquid by replacing stopper 5 and removing stopper 4. A vent may be provided in the upper stopper, closed with a pin or the finger, to vary the volume of the drop attending the lower stopper, or both stoppers may be provided with electrodes for subjecting the contents of the vessel to electrophoresis, and the tube may be used as a pipette. The stoppers may be provided with a protective smooth or glazed surface coating. The Specification as open to inspection under Sect. 91 comprises also a vessel without a taper to one or both ends. This subject-matter does not appear in the Specification as accepted.