Patent ID: 8679313

Claim:
A method for concentrating a target molecule from a fluid comprising: obtaining a first fluid having a first concentration of the target molecule and a first conductivity; selecting a second fluid, having a second conductivity, based on a relationship between the first and second conductivities, wherein the second conductivity is different from the first conductivity; flowing the first fluid into a channel through a first inlet; flowing the second fluid into the channel through a second inlet, wherein the first fluid and second fluids are in laminar flow with each other and an interface is maintained between the first and second fluids along the length of the channel; applying an electric field transverse to a length of the channel, whereby at least a portion of the target molecules in the first fluid are caused to migrate towards the second fluid; flowing a portion of the first fluid from the channel through a first outlet placed to receive the first fluid; flowing a portion of the second fluid from the channel through a second outlet placed to receive the second fluid; and continuously flowing a portion of both fluids containing a second concentration of the target molecule through a third outlet placed at about the interface between the first fluid and the second fluid, wherein the total volume of fluid flowing through the third outlet is substantially less than the volume of the first fluid flowing through the first inlet, such that the second concentration of the target molecule through the third outlet is greater than the first concentration of the target molecule.