Patent ID: 7842514

Claim:
A particle manipulation unit, comprising: a substrate; a channel formed on said substrate, comprising a first channel and a second channel branched out from said first channel, capable of manipulating direction of flow of particles flowing in a liquid in said channel; and a permeation limiting zone limiting permeation of at least a part of said particles, disposed in said first channel in the vicinity of a branching point where one or more second channels are branched out from said first channel, wherein said permeation limiting zone has a plurality of obstacles arranged to be spaced from each other, the obstacles being selected from the group consisting of cylinders, pseudo-cylinders, cones, circular cones, elliptical cones, prisms, triangular prisms and quadrangular prisms, a gap between adjacent obstacles is set to a size allowing a part of said particles to permeate therethrough, and said obstacles are arranged so that a direction of force causing flow of said particles lies non-normal to and non-parallel with a direction of arrangement of said obstacles at the front-most plane on the branching point side of said permeation limiting zone.