Patent ID: 7275858

Claim:
A microfluidic device comprising a microchannel structure in which there are one or more inlet ports, one or more outlet ports, and a structural unit in communication with at least one of said ports, wherein said structural unit is an integrated volume defining unit that enables volume-definition of an aliquot of liquid within the microchannel structure and which said volume defining unit comprises: a) a volume-defining microcavity; b) an inlet microconduit which is connected to the microcavity via an inlet opening of the microcavity; c) an outlet microconduit which is connected to the microcavity via an outlet opening of the microcavity with a valve at the joint between the outlet microconduit and the microcavity; and d) an overflow microconduit, which is connected to an overflow opening of the microcavity which overflow opening is at the same level as the joint between the inlet microconduit and the volume defining microcavity, the microcavity being constricted at the overflow opening; wherein the overflow opening is at a higher level than the outlet opening and the volume being defined as the volume between the valve and the overflow opening.