Patent ID: 7727476
Filing Date: 2010-06-01
Classification: B01L,G01F,G01N,Y10T

Abstract:
1. A device for aspirating and dispensing or for dispensing liquid samples comprising: at least one piston pump that in each case comprises a cylinder block with a cylindrical chamber having a wall, a pump piston comprising a free piston end and being movable in said cylindrical chamber, and a pump piston drive that engages the piston; at least one pipette or dispenser tip connected to the cylindrical chamber with a line in each case, and a channel or channel system that discharges into the cylindrical chamber(s) for flushing or rinsing the cylindrical chamber(s), wherein the cylinder block comprises a first part and a second part, between which first and second cylinder block parts the channel or channel system is located, wherein the first and second block parts comprise respective first and second seals, the first and second seals touching the outer surface of the pump piston for sealing the channel or channel system against the environment, wherein the free end of each pump piston is capable of being positioned between the first seal and the channel or channel system for flushing or rinsing the cylindrical chamber and is capable of being positioned between the channel or channel system and the line for aspirating or for dispensing liquid samples, and wherein the second seal entirely seals the cylindrical chamber from the channel or channel system during aspirating or dispensing liquid samples, while the free end of the pump piston is positioned between the channel or channel system and the line such that the second seal touches the outer surface of the pump piston.