Dielectrophoretic cell stream sorter

• US 5,489,506 A
• Filed: 02/16/1995
• Issued: 02/06/1996
• Est. Priority Date: 10/26/1992
• Status: Expired due to Fees

• Current Assignee: Biolife Systems Incorporated
• Original Assignee: Biolife Systems Incorporated
• Inventors: Crane, Stuart
• Primary Examiner(s): Housel, James C.
• Assistant Examiner(s): FREED, RACHEL
• Application Number:
  US08/391,403
• Time in Patent Office: 355 Days
• Field of Search: 436/63, 435/2, 435/7.24, 435/29, 356/72, 356/73, 209/3.1, 209/552, 209/571, 209/127.4, 324/71.4, 361/226, 250/461.2
• US Class Current: 435/2
• CPC Class Codes: B03C 5/026 using open-gradient differential dielectric separation, i.e. using electrodes of special shapes for non-uniform field creation, e.g. Fluid Integrated Circuit [FIC]
• CPC Class Codes: G01N 15/1031 by measuring electrical or magnetic effects
• CPC Class Codes: G01N 15/149 specially adapted for sorting particles, e.g. by their size or optical properties

Abstract

A method and apparatus for continuously sorting living cells from a mixture of many unlike cells to obtain separate populations of like cells. The invention comprises cell and fluid intake ports, a cell deflection chamber, and a series of output vacuum pumps attached to a like number of collection reservoirs. The cell intake section is a two-stage system that first mixes the incoming cells with a deionized, buffered, processing medium then sheathes the output stream with a centering carrier fluid. An expansion chamber contains one or more electrodes connected to one or more RF generators that act upon the passing cells so that they are fanned out within the expansion chamber according to their size, physical construction, chemical composition and electronic properties. Vacuum pumps draw the fluids through the system and deposit the sorted cells in separate reservoirs.

Claims

1. A method for continuously sorting selected cells from a heterogenous mixture of cells to obtain separate populations, said method comprising the steps of:

transporting living cells in a growing medium fluid into the entry port of a cell sorting apparatus;

mixing said cells into a suitable processing medium fluid to create a cell suspension;

transporting said cell suspension into an expansion chamber;

exposing said cell suspension contained within said expansion chamber to a radio frequency field to cause said living cells to move in response to said radio frequency field to different collection regions of said chamber to be separately collected; and

adjusting said radio frequency field in both frequency and strength to maximize desired sorting;

said cell suspension being vacuum drawn during said steps by a vacuum pump.

2. The method for continuously sorting living cells according to claim 1 further including the step of surrounding said cell suspension by a fluid sheath, said fluid sheath having a center, as said suspension enters said expansion chamber by holding said cell suspension in said center of said sheathing fluid.

3. The method for continuously sorting living cells according to claim 1 wherein said cell suspension is exposed to a series of radio frequency fields in sequence.

4. The method for continuously sorting living cells according to claim 1 including the additional step of depositing the sorted cells into cell recovery reservoirs after being drawn through said apparatus by said vacuum pump.

5. The method of continuously sorting living cells according to claim 1 wherein said cells sorted into said separate cell collection regions are resorted through repetition in subsequent interconnected sorting chambers.

6. The method of continuously sorting living cells according to claim 1 further including the step of subsequently sorting groups of sorted cells in a stacked expansion chambers.