Method for separating biological molecules and cells in solution

Patent metadata

Field	Value
Publication number	US-10107781-B2
Application number	US-201314417063-A
Country	US
Kind code	B2
Filing date	Jul 29, 2013
Priority date	Aug 3, 2012
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A method for separating a plurality of deformable objects, such as biological cells or biological supramolecules such as DNA, in a liquid medium by use of an electrophoretic technique combined with hydrodynamic forces. The deformable objects are introduced into a channel, having a flow axis and a cross section at right angles to the flow axis, with the minimum size of the cross section being less than or equal to 50 pm; A hydrodynamic flow is defined a in the channel together with the application of an electric field in the channel, making it possible to move the deformable objects in the channel according to the flow axis and to separate them along the flow axis. A device suitable for implementing this method. The electrolyte used for the electrophoretic separation may be a non-Newtonian fluid with viscoelastic properties.

First claim

The invention claimed is:

1. Method for separating a plurality of deformable objects in a liquid medium, comprising:
introducing the deformable objects into a single channel from an additional channel, wherein an intersection between the single channel and the additional channel defines an introduction zone, in order to obtain a homogeneous concentration of deformable objects in the introduction zone, the single channel having a flow axis and a cross section orthogonal to the flow axis, and the minimum dimension of said cross section being less than or equal to 200 μm; and
applying a hydrodynamic flow with a parabolic profile characteristic in said single channel together with the application of an electric field in said single channel, allowing the deformable objects to be displaced in the single channel according to the flow axis and to be separated along the flow axis,
wherein the liquid medium is non-Newtonian fluid.

2. Method according to claim 1 , wherein the introduction of the deformable objects is carried out in the introduction zone of the single channel, and the displacement of the deformable objects is carried out from the introduction zone to a detection zone of the single channel, the method further comprising:
detecting deformable objects which arrive in the detection zone.

3. Method according to claim 1 , wherein:
the minimum dimension of the single channel is less than or equal to 25 μm; and/or
the ratio between the minimum dimension of the cross section and the dimension of the cross section in a direction orthogonal to that of the minimum dimension is less than or equal to 1/10; and/or
the distance between the introduction zone and the detection zone of the single channel is from 500 μm to 20 cm.

4. Method according to claim 1 , wherein the liquid medium comprises uncharged polymers.

5. Method according to claim 4 , wherein the concentration of uncharged polymers is greater than or equal to the concentration from which the polymers are in contact.

6. Method according to claim 4 , wherein the uncharged polymers are chosen from polyvinylpyrrolidone, poly(ethylene glycol), polyacrylamide and mixtures thereof.

7. Method according to claim 1 , wherein the deformable objects have a modulus of elasticity less than or equal to 10 9 Pa.

8. Method according to claim 1 , wherein the deformable objects are chosen from molecules such as nucleic acid molecules, supramolecular assemblies, cells and fragments of cells.

Assignees

• Centre Nat Rech Scient

Inventors

• Bancaud Aurélien
• Ranchon Hubert

Classifications

• G01N27/44791 Primary

  Microapparatus (sample containers with integrated microfluidic structures B01L3/5027) · CPC title

• G01N27/44765

  of the counter-flow type · CPC title