Multi-stage target cell enrichment using a microfluidic device

Abstract

A microfluidic device comprises at least one inlet for receiving a sample comprising target cells and non-target cells; a first spiral channel portion having an upstream end in a central region and a downstream end in a peripheral region, the upstream end being coupled to the inlet, the first spiral channel portion being configured such that the target cells and the non-target cells occupy different streams at the downstream end; a first waste outlet arranged to couple with streams of non-target cells at the downstream end of the first spiral channel portion; a link channel portion arranged to couple with streams of target cells at the down-stream end of the first spiral channel portion; a second spiral channel portion having an upstream end in a peripheral region and a downstream end in a central region, the upstream end of the second channel portion being coupled to the link channel portion, the second spiral channel portion being configured such that the target cells and the non-target cells occupy different streams at the downstream end; a second waste outlet arranged to couple with streams of non-target cells at the downstream end of the second spiral channel portion; and a sample outlet arranged to couple with streams of target cells at the downstream end of the second spiral channel portion.

1 - 12 . (canceled) 
     
     
         13 . A microfluidic device, comprising:
 at least one inlet for receiving a sample comprising target cells and non-target cells;   a first spiral channel portion having an upstream end in a central region and a downstream end in a peripheral region, the upstream end being coupled to the inlet, the first spiral channel portion being configured such that the target cells and the non-target cells occupy different streams at the downstream end;   a first waste outlet arranged to couple with streams of non-target cells at the downstream end of the first spiral channel portion;   a link channel portion arranged to couple with streams of target cells at the downstream end of the first spiral channel portion;   a second spiral channel portion having an upstream end in a peripheral region and a downstream end in a central region, the upstream end of the second channel portion being coupled to the link channel portion, the second spiral channel portion being configured such that the target cells and the non-target cells occupy different streams at the downstream end;   a second waste outlet arranged to couple with streams of non-target cells at the downstream end of the second spiral channel portion; and   a sample outlet arranged to couple with streams of target cells at the downstream end of the second spiral channel portion;   wherein the microfluidic device further comprises a pressure compensator path coupling the downstream end of the first spiral channel portion to the first waste outlet, the pressure compensator path having a fluid resistance selected to compensate for a fluid resistance of the second spiral channel portion.   
     
     
         14 . A microfluidic device of  claim 13 , further comprising a first buffer inlet coupled to the upstream end of the first spiral channel portion, the first buffer inlet configured to receive a sheath buffer and a second buffer inlet coupled to the upstream end of the second spiral channel portion, the second buffer inlet configured to receive a sheath buffer. 
     
     
         15 . A microfluidic device of  claim 14 , wherein the first buffer inlet is arranged to introduce the sheath buffer to the first spiral channel portion adjacent to an inner wall of the first spiral channel portion and the at least one inlet is arranged to introduce the sample to the first spiral channel portion adjacent to an outer wall of the first spiral channel portion. 
     
     
         16 . A microfluidic device of  claim 13 , wherein the sample is a blood sample or blood constituents. 
     
     
         17 . A microfluidic device of  claim 13 , wherein the target cells are circulating tumor cells or circulating rare cells. 
     
     
         18 . A microfluidic device of  claim 13 , wherein the first and second spiral channel portions are configured such that the target cells undergo inertial focusing and the non-target cells migrate in lateral position under the influence of Dean forces. 
     
     
         19 . A microfluidic device of  claim 13 , wherein the target cells have a cell diameter greater than a cell diameter threshold and the non-target cells have a diameter less than the cell diameter threshold. 
     
     
         20 . A microfluidic device of  claim 13 , wherein flow resistances associated with the first waste outlet and the channel link portion are configured according to a flow ratio. 
     
     
         21 . A microfluidic device of  claim 20 , wherein channel widths associated with the first waste outlet and the channel link portion are configured according to the flow ratio. 
     
     
         22 . A microfluidic device of  claim 20 , wherein flow resistances associated with the second waste outlet and the sample outlet are configured according to the flow ratio. 
     
     
         23 . A microfluidic device of  claim 22 , wherein channel widths associated with the second waste outlet and the sample outlet are configured according to the flow ratio. 
     
     
         24 . A microfluidic device of  claim 20 , wherein the flow ratio is in the range of 0.1 to 10.