Apparatus for magnetic cell separation

• US 5,536,475 A
• Filed: 03/14/1994
• Issued: 07/16/1996
• Est. Priority Date: 10/11/1988
• Status: Expired due to Term

• Current Assignee: Nexell Therapeutics Inc. (Baxter International Inc.)
• Original Assignee: Baxter International Inc.
• Inventors: Hardwick, R. Alan, Moubayed, Ahmad-Maher
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): Ludlow, Jan M.
• Application Number:
  US08/212,479
• Time in Patent Office: 855 Days
• Field of Search: 422/44, 422/99, 422/101, 436/526, 436/806, 436/807, 436/177, 436/178, 435/2, 435/7.21, 435/7.24, 435/7.23, 435/7.25, 435/962, 435/971, 604/5, 604/6, 210/222, 210/223, 210/695, 209/217, 209/221, 209/224, 209/225, 209/232
• US Class Current: 422/44
• CPC Class Codes: A61K 35/16 Blood plasma; Blood serum umbilical cord blood A61K35/51
• CPC Class Codes: A61K 35/28 Bone marrow; Haematopoietic stem cells; Mesenchymal stem cells of any origin, e.g. adipose-derived stem cells
• CPC Class Codes: A61K 47/51 the non-active ingredient being a modifying agent
• CPC Class Codes: A61M 1/0209 Multiple bag systems for separating or storing blood components
• CPC Class Codes: A61M 1/3618 Magnetic separation
• CPC Class Codes: A61M 1/362 changing physical properties of target cells by binding them to added particles to facilitate their subsequent separation from other cells, e.g. immunoaffinity
• CPC Class Codes: B03C 1/01 by addition of magnetic adjuvants
• CPC Class Codes: B03C 1/0332 using permanent magnets
• CPC Class Codes: B03C 1/288 disposed at the outer circumference of a recipient
• CPC Class Codes: B03C 2201/18 Magnetic separation whereby the particles are suspended in a liquid
• CPC Class Codes: B03C 2201/26 for use in medical applications
• CPC Class Codes: G01N 33/491 by separating the blood components G01N15/05 takes precedence
• CPC Class Codes: G01N 33/5005 involving human or animal cells immunoassay G01N33/56966; immunoassays of protozoa G01N33/56905; protozoa in screening assays C12Q1/025
• CPC Class Codes: G01N 33/54326 Magnetic particles
• CPC Class Codes: G01N 33/56966 Animal cells
• CPC Class Codes: G01N 35/0098 involving analyte bound to insoluble magnetic carrier, e.g. using magnetic separation magnetic particles used in immunoassays G01N33/54326; magnetic separation in general B03C
• CPC Class Codes: Y10S 435/962 Prevention or removal of interfering materials or reactants or other treatment to enhance results, e.g. determining or preventing nonspecific binding
• CPC Class Codes: Y10S 435/971 Capture of complex after antigen-antibody reaction
• CPC Class Codes: Y10S 436/806 Electrical property or magnetic property
• CPC Class Codes: Y10S 436/807 Apparatus included in process claim, e.g. physical support structures

Abstract

An apparatus for magnetic cell separation using paramagnetic microbeads includes a base upon which is movably carried a rocker member. The rocker member carries both a primary processing container in which a mixture of liquid with cells and paramagnetic microbeads is received; and a primary magnet movable from a first position adjacent to the primary container to magnetically capture the microbeads, and a second position spaced from the primary container to magnetically release the microbeads. The mixture of liquid with cells and microbeads is agitated by tilting motions of the rocker assembly, thereby achieving the binding of target cells to microbeads. The paramagnetic microbeads, with bound target cells, are captured and released by movements of the primary magnet between its first and second positions. A secondary magnet is placed downstream from the primary magnet to capture any paramagnetic microbeads which might escape from the primary magnet. Also provided is an interconnected container apparatus for use to contain and appropriately conduct the liquid, cells, and microbeads.

Claims

1. Apparatus for magnetic cell separation using paramagnetic microbeads and a container set including a primary container which is substantially of elongate cylindrical shade and a secondary container, which containers may be placed in fluid communication with one another, and which containers are magnetically permeable, said apparatus comprising:

a base member, said base member movably supporting an agitation member, and first power drive means for agitating said agitation member relative to said base member;

said agitation member including means for removably securing thereto in a relatively fixed secured position the primary container within which a liquid suspension of the cells and microbeads may be agitated by movement of said agitation member;

said agitation member further movably carrying a primary magnet for movement between a first magnet position adjacent to the primary container in its secured position, in said first magnet position of said primary magnet magnetic flux penetrating the primary container in its secured position to attract and capture the microbeads, and said primary magnet being movable to a second magnet position spaced from the primary container in its secured position so that magnetic flux from said primary magnet does not capture the microbeads; and

second power drive means for selectively moving said primary magnet between said first end second magnet positions independently of agitation of said primary container;

wherein said base member further includes a holder for a secondary container, and a secondary magnet disposed adjacent to said secondary container when the latter is held on said holder for capturing paramagnetic microbeads which escape from said primary container;

wherein said base member pivotally carries said agitation member; and

wherein said agitation member is configured to secure thereto in a fixed relative position the primary container, said first power drive means also being effective to tiltingly move said agitation member and primary container between a first agitation member position in which the length of the primary container is vertical, and a second agitation member position in which the length of the primary container is horizontal.

2. The apparatus of claim 1 wherein said power drive means includes means for affecting successively opposite tilting movements of said agitation member and primary container from said horizontal second agitation member position.

3. The apparatus of claim 1 wherein said first power drive means includes a first stepper motor, and a motor drive controller for said first stepper motor.

4. The apparatus of claim 1 wherein said second power drive means includes a second stepper motor, and a motor drive controller for said second stepper motor.

5. The apparatus of claim 1 wherein said first power drive means is effective to also move said agitation member and primary container to a first separation position in which said agitation member and the primary container are angulated relative to said horizontal second agitation member position.

6. The apparatus of claim 5 wherein said first separation position is angulated relative to said horizontal agitation member position by a certain angle.

7. The apparatus of claim 6 wherein said certain angle is substantially 5 degrees.

8. The apparatus of claim 1 further including control means for controlling operation of said first and said second power drive means.

9. The apparatus of claim 8 wherein said control means includes a microprocessor-based controller, and said apparatus including an annunciator screen upon which said controller can further provide output information to a human operator of said apparatus.

10. The apparatus of claim 9 wherein said apparatus further includes an operator input device by which said human operator can make an input to said microprocessor-based controller.

11. The apparatus of claim 8 further including sensor means for indicating to said control means when said agitation member is in said first agitation member position and when said agitation member is in said second agitation member position.

12. The apparatus of claim 11 wherein said sensor means includes an encoder disk rotating with said agitation member, said encoder disk having at least one feature which is distinguishable from the remainder of said encoder disk, and at least one sensor device responsive to said at least one feature and providing an input to said control means in response to alignment of said feature with said sensor device.

13. The apparatus of claim 12 wherein said encoder disk has a first feature which aligns with said sensor device when said agitation member is in said first agitation member position, and a second similar feature which aligns with said sensor device when said agitation member is in said second agitation member position.

14. The apparatus of claim 8 further including sensor means for indicating to said control means when said primary magnet is in said first magnet position, and when said primary magnet is in said second magnet position.

15. The apparatus of claim 14 including a flag member carried with said primary magnet between said first and said second magnet positions, and respective first and second sensor devices responsive to alignment of said flag member therewith to providing a respective input to said control means.

16. Apparatus for performing magnetic cell separation using both paramagnetic microbeads and a container set including an elongate primary container in which cells and paramagnetic microbeads are receivable in liquid mixture, and a secondary container, which first and second containers of said container set are magnetically permeable and may be placed in fluid flow communication with one another, said apparatus comprising:

a base having a tower portion extending upwardly thereon, said tower portion journaling a rocker assembly for pivotal movement about a generally horizontal pivot axis, said rocker assembly including means for securing the elongate primary container thereto in a fixed relative position, said apparatus including a first power drive means both for selectively pivoting said rocker assembly about said pivot axis and for positioning said rocker assembly in selected pivotal positions including a horizontal position and a vertical position for said primary container, a primary magnet having a certain magnetic flux reach carried on said rocker assembly and movable between a first magnet position placing said primary container in its secured position on said rocker assembly within said magnetic reach so that magnetic flux from said primary magnet is effective to magnetically capture a substantial percentage of the paramagnetic microbeads in said primary container, and said primary magnet being movable to a second magnet position spaced from said primary container in its secured position on said rocker member so that said primary container is substantially not within said magnetic flux reach to thereby magnetically release said paramagnetic microbeads to mix into the liquid in the primary container, second power drive means for selectively moving said primary magnet between said first and said second magnet positions, and control means for controlling said first and said second power drive means to selectively agitate said primary container in its secured position on said rocker assembly by opposite tilting movements of said rocker assembly about said pivot axis and to selectively magnetically capture and magnetically release said paramagnetic microbeads in said primary container by respective movements of said primary magnet between its first and second magnet positions.

17. The apparatus of claim 16 wherein said base further includes said base carrying a holder for a secondary container, and a secondary magnet disposed adjacent to said secondary container for capturing paramagnetic microbeads which escape from said primary container into said secondary container.

18. The apparatus of claim 17 wherein said holder includes a rim defining a recess into which said secondary container is receivable, a door hinged on said base for closing said recess and confining said secondary container in close association with said secondary magnet, and a handle assembly for effecting opening of said door.

19. The apparatus of claim 18 wherein said door includes a frame portion formed of magnetic material and which is attracted to said secondary magnet, said handle assembly including a camming portion which engages said rim to both cam said door open in opposition to said magnetic attraction of said door frame by said secondary magnet, and to allow said door to be controllably closed in conjunction with said magnetic attraction.

20. The apparatus of claim 16 wherein said control means includes a microprocessor-based controller.

21. The apparatus of claim 20 further including both an annunciator means for visually displaying output information from said controller to a human operator of said apparatus, and an input facility by which said human operator may provide input information to said controller.

22. The apparatus of claim 21 wherein said microprocessor-based controller is programmed with all of the steps in said magnetic cell separation, said microprocessor-based controller displaying for a human operator on said annunciator means steps in said process which said human operator is to perform.