Cell separation using microchannel having patterned posts

Abstract

A micro flow device for separating or isolating cells from a bodily fluid or other liquid sample uses a flow path where straight-line flow is interrupted by a pattern of transverse posts. The posts are spaced across the width of an expanded collection chamber region in the flow path, extending between the upper and lower surfaces thereof; they have rectilinear surfaces, being curved in cross-sections, e.g. circular or tear-drop shaped, and are randomly arranged so as to disrupt streamlined flow. The device is oriented so that its lower surface is aligned at about 45° to the horizontal. Sequestering agents, such as Abs, which are attached to surfaces of the collection region via a hydrophilic coating, preferably a permeable hydrogel containing isocyanate moieties, are highly effective in capturing cells or other targeted biomolecules while the remainder of the liquid sample exits horizontally.

1 . A microflow apparatus for separating biomolecules from a sample of a bodily fluid or other liquid, which apparatus comprises:
 a body having a flow path defined as a cavity in a flat surface thereof through which such a sample containing target biomolecules can be caused to flow, the flow path having inlet means, outlet means, and a microchannel arrangement extending between said inlet and outlet means, which microchannel arrangement includes a collection region with a plurality of transverse separator posts located in said region, and   closure plate means having a flat surface that abuts said body flat surface and closes said flow path cavity,   said posts being integral with a base surface of said collection region and projecting therefrom so as to extend to the surface of said closure plate means,   said posts being arranged in an irregular pattern extending laterally across said flow path in said collection region so as to interrupt straight-line flow and streamlined flow of liquid through said region, and   wherein said posts are conjugated with sequestering agents that will bind with target biomolecules,   whereby disruption of streamlined flow throughout said collection region as a result of said irregular pattern of said posts creates effective capture of target biomolecules on said surfaces in said collection region.   
     
     
         2 . The apparatus according to  claim 1 , wherein the base surface is conjugated with sequestering agents that will bind with target biomolecules. 
     
     
         3 . The apparatus according to  claim 1 , wherein the flat surface of the closure plate is conjugated with sequestering agents that will bind with target biomolecules. 
     
     
         4 . The apparatus according to  claim 1 , wherein the microchannel comprises side walls, and wherein the side walls are conjugated with sequestering agents that will bind with target biomolecules. 
     
     
         5 . The apparatus according to  claim 1 , wherein the biomolecules are cells. 
     
     
         6 . The apparatus according to  claim 1 , wherein said posts have at least about 3 different cross sectional sizes. 
     
     
         7 . The apparatus according to  claim 1 , wherein said posts are aligned substantially perpendicular to the base surface of said microchannel. 
     
     
         8 . The apparatus according to  claim 1 , wherein said sequestering agents are covalently bound to said posts using polyethylene glycol (PEG) or polypropylene glycol (PPG). 
     
     
         9 . The apparatus according to  claim 1 , wherein said sequestering agents are coupled to said posts through bifunctional coupling agents. 
     
     
         10 . The apparatus according to  claim 1 , wherein the closure plate and base surface are fabricated of plastic. 
     
     
         11 . The apparatus according to  claim 1 , wherein the sequestering agents are selected from the group consisting of antibodies, avidin, and streptavidin. 
     
     
         12 . The apparatus according to  claim 1 , wherein fluid flow through the microchannel is driven using a pump. 
     
     
         13 . The apparatus according to  claim 12 , wherein the pump is a peristaltic pump. 
     
     
         14 . The apparatus according to  claim 1 , wherein the inlet means comprises a fluid reservoir. 
     
     
         15 . The apparatus according to  claim 1 , wherein the biomolecule is recovered by cleaving the sequestering agent. 
     
     
         16 . The apparatus according to  claim 1 , wherein a linker attaches the target biomolecule to the sequestering agent. 
     
     
         17 . The apparatus according to  claim 16 , wherein the linker is a cleavable linker, and wherein the biomolecule is recovered by cleaving the linker. 
     
     
         18 . The apparatus according to  claim 1 , wherein the flow through for capturing biological substances within the microchannel is at a rate of 0.1 to 2 mm/sec. 
     
     
         19 . The apparatus according to  claim 10 , wherein the plastic is a moldable plastic.