Flow cytometer

• US 5,464,581 A
• Filed: 08/02/1993
• Issued: 11/07/1995
• Est. Priority Date: 08/02/1993
• Status: Expired due to Term

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: van den Engh, Ger
• Primary Examiner(s): Housel, James C.
• Assistant Examiner(s): FREED, RACHEL
• Application Number:
  US08/100,763
• Time in Patent Office: 827 Days
• Field of Search: 324/71.4, 324/71.1, 209/3.1, 209/564, 209/579, 209/906, 250/461.2, 250/227.11, 422/82.01, 422/82.05, 422/82.08, 422/68.1, 436/63, 436/149, 436/150, 436/164, 436/806, 73/61.48, 73/61.71
• US Class Current: 422/82.01
• CPC Class Codes: G01N 15/14 Optical investigation techniques, e.g. flow cytometry
• CPC Class Codes: G01N 15/149 specially adapted for sorting particles, e.g. by their size or optical properties

Abstract

A Faraday cage enclosing the flow chamber of a cytometer and ground planes associated with each field deflection plate in concert therewith inhibit electric fields from varying the charge on designated events/droplets and further concentrates and increases forces applied to a charged event passing therethrough for accurate focus thereof while concomitantly inhibiting a potential shock hazard.

Claims

1. Cytometer apparatus for sorting cells and particles, comprising:

a. a flow chamber providing a flow of charged particles,

b. a Faraday shield enclosing said flow chamber,

c. a pair of oppositely charged deflection plates disposed on either side of said charged particle flow, each having an internal surface facing said particle flow, an opposed external surface, and vertical sides,

d. ground planes surrounding and spaced apart from the external surface and vertical sides of each said deflection plate, and

e. insulation means located in the space between each of said charged deflection plates and its associated ground plane.

2. Cytometer apparatus according to claim 1, wherein said Faraday shield is provided with passages therethrough for operation upon said charged particle flow by at least one laser.

3. Cytometer apparatus according to claim 2, wherein said Faraday shield is provided with means for detecting laser scatter and event luminescence.

4. Cytometer apparatus according to claim 1, wherein said deflection plates comprise a pair of rectangular shaped conductor plates oriented longitudinally along said particle flow.

5. Cytometer apparatus according to claim 1, wherein each said internal surface of said deflection plates is covered with a nonconductor.

6. Cytometer apparatus according to claim 1 wherein the flow chamber includes means for forming fluid droplets, and the charged particles are contained in said droplets.

7. Cytometer apparatus according to claim 1 wherein the deflection plates are charged to about +3000 V and -3000 V respectively.