Magnetic separation apparatus and methods employing an internal magnetic capture gradient and an external transport force
AssigneeImmunivest Corporation
InventorsGerald J. Dolan, Leon W. M. M. Terstappen
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Abstract
The present invention relates to apparatus and methods for separating, immobilizing, and quantifying biological substances from within a fluid medium. Biological substances are observed by employing a high internal gradient magnetic capture structure formed within a vessel, in conjunction with an externally-applied force for transporting magnetically responsive material toward the capture structure. The invention is also useful in conducting quantitative analysis and sample preparation in conjunction with automated cell enumeration techniques.
Claims28
An.apparatus for observing magnetically-reponsive microscopic entitities suspended in a fluid medium, comprising:
- a vessel having a transparent wall and a chamber formed therein for containing the fluid medium;
- a ferromagnetic capture structure lithographically formed on the transparent wall;
- and
- magnetic means for inducing an internal magnetic gradient in the vicinity of the ferromagnetic capture structure, whereby the magnetically-responsive entities are immobilized along the wall adjacent to the capture structure.
An apparatus for observing magnetically-reponsive microscopic entitities suspended in a fluid medium, comprising:
- a vessel having a transparent wall and a chamber formed therein for containing the fluid medium;
- a ferromagnetic capture structure supported on the transparent wall;
- magnetic means for inducing an internal magnetic gradient in the vicinity of the ferromagnetic capture structure, whereby the magnetically-responsive entities are immobilized along the wall adjacent to the capture structure;
- and
- an automated optical observation system for detecting and enumerating the immobilized entities;
- wherein the automated observation system comprises:
- an optical detector for detecting said immobilized entities;
- and
- optical tracking means for scanning the optical detector along the capture structure.
An apparatus for observing magnetically-reponsive microscopic entitities suspended in a fluid medium, comprising:
- a vessel having a transparent wall and a chamber formed therein for containing the fluid medium;
- a ferromagnetic capture structure supported on the transparent wall;
- magnetic means for inducing an internal magnetic gradient in the vicinity of the ferromagnetic capture structure, and for applying an external gradient perpendicular to the ferromagnetic capture structure, whereby the magnetically-responsive entities are transported toward and immobilized along the wall adjacent to the capture structure.
A method of immobilizing microscopic magnetically-responsive entities suspended in a fluid medium for observation, comprising the steps of:
- providing a vessel having a chamber with a transparent wall and a ferromagnetic capture structure supported on the wall;
- introducing the fluid medium into the chamber;
- applying a magnetic field to the chamber to induce an internal magnetic gradient in the vicinity of the ferromagnetic capture structure;
- immobilizing the magnetically-responsive entities in a line against the transparent wall and adjacent to the ferromagnetic capture structure;
- and
- observing the magnetically responsive entities held against the wall adjacent to the ferromagnetic capture structure.
A method of immobilizing microscopic magnetically-responsive entities suspended in a fluid medium for observation, comprising the steps of:
- providing a vessel having a chamber with a transparent wall and a ferromagnetic capture structure supported on the wall;
- introducing the fluid medium into the chamber;
- applying a magnetic field having an external gradient to the chamber to induce an internal magnetic gradient in the vicinity of the ferromagnetic capture structure and to transport magnetically-responsive entities toward the capture structure;
- collecting said magnetically-responsive entities in a linear monolayer against the wall and adjacent to the ferromagnetic capture structure;
- and
- observing the magnetically responsive entities held against the wall adjacent to the ferromagnetic capture structure.
A method of immobilizing microscopic magnetically-responsive entities suspended in a fluid medium for observation, comprising the steps of:
- providing a vessel having a chamber with a transparent wall and a ferromagnetic capture structure supported on the wall;
- introducing the fluid medium into the chamber;
- applying a magnetic field to the chamber to induce an internal magnetic gradient region in the vicinity of the ferromagnetic capture structure;
- applying a transport force to entities located in the chamber substantially out of range of the internal magnetic gradient region to transport magnetically-responsive entities toward the internal magnetic gradient region;
- collecting said magnetically-responsive entities in a linear monolayer against the wall and adjacent to the ferromagnetic capture structure for substantialy unobstructed observation through the wall;
- and
- observing the magnetically responsive entities through the transparent wall against the wall adjacent to the ferromagnetic capture structure.
Dependencies are inferred from the claim text.