MICROFLUIDIC IMPEDANCE FLOW CYTOMETER

• US 20150308971A1
• Filed: 04/20/2012
• Published: 10/29/2015
• Est. Priority Date: 04/20/2012
• Status: Abandoned Application

• Current Assignee: AcouSort AB
• Original Assignee: FOSS Analytical A/S
• Inventors: BISGAARD, Christer, LAURELL, Thomas, GRENVALL, Carl, ANTFOLK, Christian
• Application Number:
  US14/395,686
• Publication Number:
  US 20150308971A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01N 15/12 by observing changes in resistance or impedance across apertures when traversed by individual particles, e.g. by using the Coulter principle
• CPC Class Codes: G01N 2015/1024 Counting particles by non-optical means
• CPC Class Codes: G01N 2015/133 Flow forming
• CPC Class Codes: G01N 2015/142 Acoustic or ultrasonic focussing
• CPC Class Codes: G01N 27/02 by investigating impedance

Abstract

A microfluidic impedance flow cytometer (‘MIC’) device (2) comprises a substrate (4) in which is formed at least one flow channel (6) for leading through a particle (22) containing fluidic sample. The flow channel (6) is formed with a focusing zone (12) and a measurement zone (14) located downstream of the focusing zone (12) in the direction of through flow and provided with an electrode arrangement (18) for characterising particles (22) in the flowing fluidic sample by means of electrical impedance wherein an acoustophoretic particle focusing arrangement (20) is provided in acoustic coupling to the flow channel (6) in the focusing zone (12) to induce acoustic forces in fluid in the flow channel (6) so as to effect a lateral and/or vertical focusing of particles before flowing to the measurement zone (14).

Claims

1. A microfluidic impedance flow cytometer (‘

MIC’

) device (2) comprising a substrate (4) in which is formed at least one flow channel (6) for leading through a particle (22) containing fluidic sample, the flow channel (6) comprising a focusing zone (12) and a measurement zone (14) located downstream of the focusing zone (12) and provided with an electrode arrangement (18) for characterising particles (22) in the flowing fluidic sample by means of electrical impedance characterised in that an acoustophoretic particle focusing arrangement (20) is provided in acoustic coupling to the flow channel (6) in the focusing zone (12).

2. A MIC device (2) as claimed in claim 1 characterised in that the acoustophoretic particle focusing arrangement comprises one or more ultrasound generators (20) acoustically coupled to a suitably dimensioned portion of the flow channel (6) of the focusing zone (12) to provide, when activated, a standing ultrasound wave in an associated one or both a lateral and a vertical dimension of the flow channel (6) of the focusing zone (12).

3. A MIC device (2) as claimed in claim 2 characterised in that the acoustophoretic particle focusing arrangement (20) is adapted to generate ultrasound to simultaneously provide a half standing ultrasound wave in both a lateral and a vertical dimension.

4. A MIC device as claimed in any preceding claim characterised in that the electrode arrangement (18) comprises a plurality of planar electrodes (18a . . . g) provided across on side of a measurement channel (16) of the measurement zone (14).

5. A method for performing flow cytometry in a microfluidic impedance flow cytometer (MIC) having a flow channel formed in a substrate, comprising the steps of:

focusing particles within a flowing fluidic sample stream in one or both a lateral or a vertical direction with respect to the direction of flow by applying ultrasound acoustic energy to the sample stream within a suitably dimensioned portion of a flow channel of the microfluidic device;

detecting, at a measurement zone of the flow channel electrical, impedance changes using an electrode arrangement located at that zone; and

analyzing in an analyzer connected to the electrode arrangement the detected impedance changes to provide one or both quantitative and qualitative information on particles within the flowing fluidic sample.