Microflow System for Particle Separation and Analysis

Abstract

A micro flow system is provided for separating particles, comprising a microfabricated member having a flow channel ( 5 ) defined therein for guiding a flow of a fluid containing the particles through the flow channel, first inlet means ( 2 ) positioned at one end of the flow channel for entering the fluid into the flow channel, first outlet means ( 7 ) positioned at the other end of the flow channel for discharging the fluid from the flow channel, the flow of the fluid containing the particles being controlled in such a way that one particle at the time passes a cross section of the flow channel, the member being positioned in a field that is substantially perpendicular to a longitudinal axis of the flow channel so that particles residing in the flow channel and being susceptible to the field across the flow channel are deflected in the direction of the field. Further, a micro flow system is provided for analyzing components of a fluid comprising a microfabricated member having a flow channel defined therein for guiding a flow of a fluid through the flow channel, first inlet means for entering particles into the flow channel, first outlet means for discharging of fluid from the flow channel and a plurality of assay sites located in the flow channel and comprising immobilized reagents whereby the fluid may be analyzed for a plurality of components while residing in the flow channel.

1 . A method of analysing components of a fluid, the method comprising: 
 (a) providing a flow channel, said flow channel having a plurality of assay sites each of which assay sites comprises immobilised probes, receptors, reagents, or indicators whereby the fluid can be analyzed for a plurality of components while residing in said flow channel;    (b) entering a fluid containing the particles into a flow channel; and    (c) allowing the fluid to flow in the channel.    
   
   
       2 . A method of forming assay sites comprising immobilised probes, receptors, reagents, or indicators in a flow channel, the method comprising: 
 (a) preparing selected surfaces of the assay sites for immobilisation of selected reagents,    (b) dispensing a selected probe, receptor, reagent, or indicator proximate to a corresponding selected assay site, and    (c) generating a field proximate to said corresponding selected assay site whereby said selected probe, receptor, reagent, or indicator is attracted towards and brought into contact with a surface of said corresponding selected assay site by said generated field and said selected probe, receptor, reagent, or indicator is immobilised upon contact with said surface.    
   
   
       3 . The method according to  claim 2 , wherein said assay sites are sequentially loaded with a probe, receptor, reagent, or indicator.  
   
   
       4 . A method according to  claim 2 , wherein said assay sites comprise a plurality of assay sites each equipped with a field generator which can be individually turned on and off.  
   
   
       5 . A method according to  claim 2 , wherein said flow channel has rectangular electrodes each electrode having selectively applied a voltage.  
   
   
       6 . A method according to  claim 2 , wherein one or more specific electrodes is applied a voltage, and a fluid containing said probe, receptor, reagent, or indicator is introduced into the micro flow channel for attracting said specific probe, reagent, or indicator to said one or more specific electrodes.  
   
   
       7 . A method according to  claim 6 , wherein said applied voltage to said one or more specific electrodes is turned off; a voltage is applied to a next electrode, and a next fluid containing a probe, receptor, reagent, or indicator is introduced into the micro flow channel.  
   
   
       8 . A method according to  claim 2 , wherein said selected probe is selected from the group consisting of antibodies, fluorescence molecules, DNA, RNA and protein dyes.  
   
   
       9 . A method according to  claim 2 , wherein the flow channel has an array of electromagnets positioned in or near its surface.  
   
   
       10 . A method according to  claim 2 , wherein said selected probe is a DNA-coated magnetic particle.  
   
   
       11 . A method according to  claim 2 , wherein said selected probe, receptor, reagent, or indicator is immobilised upon contact with said surface by covalent coupling of molecules or particles.  
   
   
       12 . A method according to  claim 11 , wherein said molecules or particles are covalently coupled by a photoactivation process.  
   
   
       13 . A method according to  claim 2 , wherein the surface of the flow channel and/or the electrodes or magnets are provided specific chemical and mechanical properties by modification or coating.  
   
   
       14 . A method according to  claim 2 , wherein said generated field is an electric field, a magnetic field, a gravitational field, and any combination thereof.  
   
   
       15 . A method according to  claim 2 , wherein said (b) dispensing of a selected probe, receptor, reagent, or indicator proximate to a corresponding selected assay site, optionally repeated for other probes, receptors, reagents, or indicators at other assay sites, is performed in an open micro flow channel on a separate cartridge; and 
 said separate cartridge is covered with a transparent cartridge component to allow said assay sites with probes, receptors, reagents, or indicators inside the flow channel to be observed.    
   
   
       16 . A method according to  claim 15  wherein said (b) dispensing of a selected probe, receptor, reagent, or indicator proximate to a corresponding selected assay site, optionally repeated for other probes, receptors, reagents, or indicators at other assay sites, is performed by inkjet based dispenser technology.  
   
   
       17 . The method according to  claim 1 , wherein an optical detector is used to analyse reactions in the micro flow system.