Method and device for concentrating molecules or objects dissolved in solution

A process for concentrating electrically charged objects in a non-newtonian liquid medium, comprising:

• the introduction of a sample containing electrically charged objects into a channel exhibiting a flow axis, a first transverse section orthogonal to the flow axis and at least one second transverse section orthogonal to the flow axis, the minimum dimension of said second transverse section being less than the corresponding dimension of said first transverse section, wherein temperatures within the first transverse section and within the second transverse section are at ambient temperature, the electrically charged objects being intended to migrate along the flow axis from a first reservoir to a second reservoir;
• the application of a hydrodynamic flow, in the first and second reservoirs by means of pressure control means of the first reservoir and of the second reservoir, in a direction of said channel in conjunction with the application, in the reverse direction, of a non-alternating electric field in said channel by means of electrodes in the first and second reservoirs, making it possible to displace the electrically charged objects in the channel along the flow axis of the first transverse section toward the second section and to halt them and to concentrate them in at least one zone upstream of said second transverse section.