BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of sample isolation, and more particularly to sample isolation using centrifugal and magnetic forces.

2. Description of Related Art

Conventional sample isolation apparatus and methods utilizing magnetic or centrifugal forces suffer notable disadvantages, including those discussed below.

For example, typical magnetic separation devices (e.g. often referred to as magnetic stands or magnetic racks) are designed to hold a sample-containing tube in a vertical position with magnets vertically situated and parallel to the tube center axis. These traditional devices condense magnetic beads along the tube wall closest to the magnet. This configuration can be suitable for placing a pipette to the bottom of the tube to aspirate supernatant without aspirating magnetic beads. However, with this configuration, some supernatant remains on the beads due to surface tension. This remaining supernatant can cause contamination carryover into the next step in the process and may affect the purity of the final eluate.

In addition, traditional centrifugation apparatus and methods result in the magnetic beads pelleting at the bottom of the centrifuge immersed in the supernatant. These approaches are less efficient than using the traditional magnetic separation devices. For example, the magnetic beads are likely to be aspirated when the supernatant is removed from the pellet. Accordingly, a portion of the sample will be lost during the aspiration process and will not be available for analysis.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present disclosure combine both magnetic isolation and centrifugation in one device. This approach can improve the efficiency of sample isolation (e.g. magnetic bead DNA/RNA isolation) by allowing for less carry over of supernatant. This can further result in cleaner preparation and reduced tube handling.

Exemplary embodiments include a device for isolating a sample, where the device comprises: a planar member comprising an upper planar surface, a lower planar surface, a central portion and an outer portion; a bearing positioned in the central portion of the planar member; and a support member proximal to the central portion of the planar member. In certain embodiments, the bearing comprises a first bearing race and a second bearing race, where the first bearing race and second bearing race are configured to rotate with respect to each other; the planar member is coupled to the first bearing race of the bearing; the support member is coupled to the second bearing race of the bearing; the outer portion of the planar member comprises a plurality of apertures distal to the central portion; each aperture of the plurality of apertures extends through the planar member at an angle to the planar member, where the angle to the planar member is between 30 degrees and 50 degrees when measured from a central axis of the aperture to the upper planar surface between the aperture and the central portion; the outer portion of the planar member comprises a plurality of magnets positioned such that each magnet in the plurality of magnets is located between the bearing and an aperture in plurality of apertures; and the device is configured to allow rotation of the planar member around the support member.

In particular embodiments, the angle to the planar member is between 35 and 45 degrees, or more specifically between 37 and 41 degrees, or more specifically approximately 39 degrees. In some embodiments, each magnet of the plurality of magnets is inserted in the lower planar surface of the planar member. In specific embodiments, the plurality of magnets comprises 52 percent Neodymium. In certain embodiments, each aperture of the plurality of apertures is tapered such that each aperture is larger at the upper planar surface than the aperture is at the lower planar surface. In particular embodiments, each aperture of the plurality of apertures is configured such that each aperture is configured to receive a tubular member comprising a cylindrical upper portion and a tapered conical lower portion.

In some embodiments, each aperture is of the plurality of apertures configured such that substantially all of a surface of the planar member surrounding each aperture maintains contact with the tubular member when the tubular member is inserted into the aperture. In specific embodiments, a surface of the planar member surrounds each aperture; the surface of the planar member surrounding each aperture comprises a cylindrical portion proximal to the upper planar surface of the planar member; and the surface of the planar member surrounding each aperture comprises a tapered conical portion proximal to the lower planar surface of the planar member.

In certain embodiments, the planar member comprises a central axis at the center of the bearing; the surface of the planar member surrounding each aperture comprises an interface between the cylindrical portion and the tapered conical portion; and the point of the interface that is closest to the central axis is substantially equidistant from the upper planar surface and the lower planar surface. In particular embodiments, each aperture in the plurality of apertures comprises a central axis at the center of the aperture; the surface of the planar member surrounding each aperture comprises an interface between the cylindrical portion and the tapered conical portion; the interface intersects the upper planar surface at a first point and a second point; the central axis of the aperture extends through the upper planar surface at a third point; and the first point, the second point, and the third point are substantially collinear.

Certain embodiments further comprise a base member configured to engage the support member. In particular embodiments, the base member comprises a plurality of electromagnets. In some embodiments, the plurality of electromagnets are arranged in a circle. Specific embodiments further comprise a control system configured to activate and deactivate each electromagnet in the plurality of electromagnets. In certain embodiments, the control system is configured to simultaneously activate a number of electromagnets in the plurality of electromagnets, wherein the number of electromagnets simultaneously activated is equal to the number of magnets in the plurality of magnets of the planar member. In particular embodiments, the control system is configured to sequentially activate and deactivate the plurality of electromagnets in the circle. In some embodiments, the plurality of magnets in the planar member are in a first plane; the plurality of electromagnets are in a second plane; and the base member comprises an elevated central portion configured to engage the support member such that the first plane is separated from the second plane by a gap between 1.0 and 4.0 mm. In specific embodiments, the outer portion of the planar member comprises a plurality of arms extending from central portion. In certain embodiments, the plurality of arms comprises three arms. In particular embodiments, the support member extends through the bearing positioned in the central portion of the planar member. In some embodiments, the support member comprises a first portion and a second portion, where: the first portion is configured to couple to the second portion; and the first portion and the second portion are configured such that the support member extends through the bearing when the first portion is coupled to the second portion. In specific embodiments, the first portion and the second portion are configured to threadably couple to each other.

Exemplary embodiments include a method of isolating a sample, where the method comprises: placing a tubular member in an aperture of a device as described herein (including for example, the device of claim1), where the tubular member comprises a sample including a liquid comprising macromolecules and a solid; rotating the planar member around the support member; and aspirating a portion of the liquid from the tubular member. In certain embodiments, the solid is a magnetic solid and wherein the magnetic solid adsorbs macromolecules and is retained by a magnet when the first and second portions of the liquid are aspirated. Particular embodiments, further comprise aspirating an initial portion of liquid from the tubular member prior to rotating the planar member around the support member.

Exemplary embodiments include a device for isolating a sample, where the device comprises: a planar member comprising a plurality of sides, an upper planar surface, a lower planar surface, a central portion and an outer portion; a bearing positioned in the central portion of the planar member; and a support member proximal to the central portion of the planar member, where: the bearing comprises a first bearing race and a second bearing race, wherein the first bearing race and second bearing race are configured to rotate with respect to each other; the planar member is coupled to the first bearing race of the bearing; the support member is coupled to the second bearing race of the bearing; the outer portion of the planar member is coupled to the central portion at each side of the planar member; the outer portion of the planar member is coupled to the central portion at an angle between 125 degrees and 145 degrees; the outer portion comprises a plurality of apertures at each side of the planar member; and the device is configured to allow rotation of the planar member around the support member.

In certain embodiments, the outer portion comprises eight apertures at each side of the planar member. In particular embodiments, the outer portion of the planar member is coupled to the central portion at an angle of approximately 135 degrees. Specific embodiments further comprise a base member, wherein: the base member comprises a plurality of sides equal to the number of sides of the planar member; and each side of the base member comprises a plurality of magnets equal to the number of apertures at each side of the planar member. In certain embodiments, the base member is configured to support the support member, the bearing and the planar member to allow rotation of the planar member with respect to the support member. In particular embodiments, the plurality of magnets comprises 52 percent Neodymium.

Exemplary embodiments include a method of isolating a sample, where the method comprises: placing a tubular member in an aperture of the device as described herein (including for example, the device of claim1), where the tubular member comprises a sample including a liquid comprising macromolecules and a solid; rotating the planar member around the support member; and aspirating a portion of the liquid from the tubular member. In certain embodiments the solid is a magnetic solid and the magnetic solid adsorbs macromolecules and is retained by a magnet when the first and second portions of the liquid are aspirated. Particular embodiments further comprise aspirating an initial portion of liquid from the tubular member prior to rotating the planar member around the support member.

Exemplary embodiments include a device for isolating a sample, where the device comprises: a first three-sided planar member; the first three-sided member further comprising a centered opening for axial rotation around a shaft; each side of the three-sided members further comprising a rectangular planar member projecting at an angle from a side of the three-sided member configured with a plurality of circular openings for receiving microcentrifuge tubes or strips of connected microcentrifuge tubes; a second base member further comprising a raised shelf configured for receiving a rolling bearing, a circular base and a shelf and a shaft projecting from the base and shelf, wherein the shaft has external threading or another fastening means for allowing rotation of the first three-sided planar member by application of a torque (rotational force) by hand; a button comprising internal thread or for receiving the external thread of the shaft or another fastening means for securing the shaft; a bearing positioned in contact with the top of the shelf of the second base member and bottom of the first planar member; and an optional third riser member configured to mate with the top of the second base member and the bottom of the first three-sided member for elevating the second base member and first three-sided planar member from a surface providing for clearance for rotational motion of the first planar member's microfuge tubes or strips of connected microfuge tubes positioned in the plurality of circular openings of each of the rectangular planar member of the first three-sided member.

Exemplary embodiments include a modular biological sample isolation device comprising: a first three-sided planar member; the first three-sided member further comprising a centered opening for axial rotation around a shaft; each side of the three-sided members further comprising a rectangular planar member projecting at an angle from a side of the three-sided member configured with a plurality of circular openings for receiving microcentrifuge tubes or strips of connected microcentrifuge tubes; a second base member further comprising a raised shelf configured for receiving a rolling bearing, a circular base and a shelf and a shaft projecting from the base and shelf, wherein the shaft has external threading or another fastening means for allowing rotation of the first three-sided planar member by application of a torque (rotational force) by hand; a button comprising internal thread or for receiving the external thread of the shaft or another fastening means for securing the shaft; a bearing positioned in contact with the top of the shelf of the second base member and bottom of the first planar member; and an optional third riser member configured to mate with the top of the second base member and the bottom of the first three-sided member for elevating the second base member and first three-sided planar member from a surface providing for clearance for rotational motion of the first planar member's microfuge tubes or strips of connected microfuge tubes positioned in the plurality of circular openings of each of the rectangular planar member of the first three-sided member.

Exemplary embodiments include a modular biological sample isolation device comprising: a first planar member with a plurality of lobes further comprising a centered opening through the member relative to the axis of rotational motion for axial rotation around a shaft; each of the three lobes further comprising a centered and angled opening through the planar member for receiving a microcentrifuge tube so that the microcentrifuge tube is seated in the opening at an angle; a magnet positioned into the first planar member on the side of the centered or off-set opening for axial rotation and adjacent to the opening for receiving a microcentrifuge tube on each of the lobes so that the magnetic force is exerted across the microcentrifuge tube's diameter; a second base member further comprising a raised shelf configured for receiving a rolling bearing, a circular base and a shaft projecting from the base, wherein the shaft has external threading or another fastening means for allowing rotation of the first three-sided planar member by application of a torque or rotational force by hand; a button member comprising internal thread or for receiving the external thread of the shaft or another fastening means for securing the shaft and for providing a surface for application of a torque or rotational force by hand; a bearing positioned in contact with the top of the shelf of the second base member and bottom of the first planar member; and a riser member for elevating the second base member and first three-sided planar member from a surface providing for clearance for rotational motion of the first planar member's microfuge tubes or strips of connected microfuge tubes positioned in the plurality of circular openings of each of the rectangular planar member of the first three-sided member.

Certain embodiments further comprise a magnetic base. In particular embodiments, the centered opening is about 10 mm to about 22 mm. In specific embodiments, the members are made of a material selected from the group consisting of printed or molded plastic or other polymer, wood, and metal. In certain embodiments, the bearing is selected from the group consisting of a rolling element bearing, a magnetic bearing, a jewel bearing, a fluid bearing, a flexure bearing, and a plurality of plain bearings. In particular embodiments, the plurality of openings of the rectangular planar member is eight openings. In some embodiments, the diameter of the openings is about 7 mm and the spacing between openings is about 2.2.mm. In specific embodiments, the rectangular planar member is angled at about 45° relative to the planar ember surface. In certain embodiments, the first planar member is about 3.5 to about 7.0 mm in thickness. In particular embodiments, the second member is round with a diameter of about 45 mm and a thickness of about 3.5 to about 7.0 mm. In some embodiments, the shelf of the second base member is about 12 mm is diameter and the shaft is about 8 mm in diameter. In specific embodiments, the shaft is about 5.5 mm to about 9.0 mm in height from the upper surface of the second member. In certain embodiments, the torque or rotational force is applied by hand or via other mechanical or electronical means for providing torque or rotational force.

Using exemplary embodiments of the present disclosure (sometimes referred to herein by the commercial name “Fuge-It”), excess supernatant that is held to the magnetic beads can be removed via centrifugation. This can be accomplished without disturbing the placement of the magnetic bead pellet, allowing the user to aspirate remaining supernatant, thereby reducing the amount of carryover between steps.

As used in this specification, “a” or “an” may mean one or more. As used herein in the claim(s), when used in conjunction with the word “comprising,” the words “a” or “an” may mean one or more than one.

The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.” As used herein “another” may mean at least a second or more.

Throughout this application, the term “about”, “approximately” or related terms are used to indicate that a value includes the inherent variation of error for the device, the method being employed to determine the value, or the variation that exists among the study subjects.

Any embodiment of any of the present methods, kits, and compositions may consist of or consist essentially of—rather than comprise/include/contain/have—the described features and/or steps. Thus, in any of the claims, the term “consisting of” or “consisting essentially of” may be substituted for any of the open-ended linking verbs recited above, in order to change the scope of a given claim from what it would otherwise be using the open-ended linking verb.

Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

