Methods and apparatus are described for the processing particles in which the particles suspended in a first fluid are introduced under laminar flow conditions into at least one first microchamber or first region, in which a second fluid is introduced under laminar flow conditions into at least one second region or second microchamber, in such a way as not to mix with the first fluid, and in which at least one field of force acting on the particles is activated in the microchamber(s), to provoke a shift of the particles alone in a predetermined direction and to transfer the same in suspension into the second fluid.