HK1115435A - Methods and systems for positioning microspheres for imaging - Google Patents

Description

Method and system for localizing microspheres for imaging

Technical Field

The present invention relates generally to methods and systems for positioning microspheres for imaging. Particular embodiments include applying a force to the microspheres through the filter media to position the microspheres over the openings in the filter media. The openings are spaced approximately equidistant across the filter media.

Background

The following descriptions and examples are not admitted to be prior art by virtue of their inclusion in this section.

Spectroscopic techniques are widely used in the analysis of chemical and biological systems. These techniques most often involve measuring the absorption or emission of electromagnetic radiation by the material of interest. One such application is in the field of microarrays, which is a technology employed by a large number of disciplines including the combinatorial chemistry and bioassay industries. Luminex Corporation of Austin, Tex has developed a system for performing bioassays on the surface of fluorescent microspheres of various colors. One example of such a system is shown in U.S. patent No.5,981,180 to Chandler et al, which is incorporated by reference herein in its entirety for all purposes. In such fluid flow devices, the microspheres are interrogated by laser excitation and fluorescence detection of each individual microsphere as it passes through the detection zone at a relatively high velocity. The measurements of such a system can be easily exported to a database for further analysis.

In the above systems, the fluorochrome is absorbed into the microsphere and/or bound to the surface of the microsphere. These dyes are selected based on their properties to emit light within the wavelength of the selected detection window. In addition, the detection windows are separated by a number of wavelengths, and the dyes are designed to minimize overlap of the dye fluorescence signals within adjacent detection windows. By using two detection windows and two dyes at 10 different concentrations, 100 sets of fluorescently distinguishable microspheres will thus be obtained.

One or more biomolecules may also be bound to the surface of the microspheres. These one or more biomolecules are selected to be achieved using microspheres based on the particular assay. For example, a population of microspheres may include different subsets of microspheres that are each coupled to a different antigen. These subsets can be combined with a sample, and assays can be performed to determine which antibodies are present in the sample. The biomolecules bound to the microspheres may include any biomolecules known in the art.

The system described above performs measurements on the microspheres as they flow through the detection window. These systems provide excellent measurements of the intensity of light scattered by the microspheres, and the intensity of light emitted by one or more fluorochromes coupled to the microspheres. However, in some instances, it may be desirable to image the microspheres in order to obtain additional or different information about the microspheres and/or the reactions that are or have occurred on the surface of the microspheres. Imaging of microspheres as they flow through the above-described system may not be possible due to performance limitations of commercially available or economically viable imaging components, for example. For example, microspheres typically move through an illumination and detection zone at relatively high speeds, which limits the time available for microsphere imaging. In this way, the imaging of the microspheres (if formed completely) may be of poor imaging quality, and thus may not provide any useful information about the microspheres.

It is therefore apparent that attempts can be made to improve the image quality of microspheres by reducing the speed at which they move through the illumination and detection zones, thereby increasing the time available for imaging. However, reducing the speed at which the microspheres move through the illumination and detection zones so that imaging can be performed would adversely reduce the throughput of the other measurements described above (measurement of the intensity of scattered light and the intensity of fluorescence). In addition, reducing the speed at which the microspheres move through the illumination and detection zones may not eliminate all of the obstacles to adequately imaging the microspheres. For example, a solution having microspheres disposed therein may adversely affect image quality when flowing through the system.

In order to form a useful microsphere image, it may be necessary to immobilize the microspheres in some manner. In addition, it may be desirable to immobilize the microspheres such that the position of the microspheres is sufficiently stable for the length of time required to image the microspheres. While many systems and methods are currently available for immobilizing microspheres, these methods are generally not suitable for use in positioning microspheres for imaging. For example, some microsphere fixation systems may be of materials that prevent sufficient illumination of the imaging microspheres. In addition, the configuration of these microsphere fixation systems may prevent adequate illumination of the microspheres and collection of light from the microspheres. Furthermore, systems configured to immobilize microspheres for purposes other than imaging tend to immobilize the microspheres without regard to the spacing between the microspheres. However, proper spacing between microspheres is an important factor in determining whether an image of immobilized microspheres can be formed with satisfactory image quality.

Accordingly, it would be beneficial to develop methods and systems for localizing microspheres for imaging that allow for adequate illumination of the immobilized microspheres, adequate collection of light from the microspheres, and suitable spacing between immobilized microspheres for imaging.

Disclosure of Invention

The following description of various system and method embodiments is not to be construed in any way as limiting the subject matter of the appended claims.

One embodiment relates to a system configured to position microspheres for imaging. The positioning of the microspheres may be performed as a preparatory (preparatory) step prior to imaging. The system includes a filter media with an opening. The openings are spaced apart in a substantially equidistant pattern across the filter media. The system also includes a flow subsystem coupled to the filter media. The flow subsystem is configured to apply a force to the microspheres to position the microspheres over the openings.

In one embodiment, the flow subsystem is configured to apply force via suction-assisted filtration. In one embodiment, the diameter of the opening is smaller than the diameter of the microsphere. In addition, the diameter of the opening is larger than the diameter of the fine hole of the filter medium. In one embodiment, the number of openings in the filter media is approximately equal to the number of microspheres to be positioned. Alternatively, the number of openings in the filter media may be greater or less than the number of microspheres. These openings may extend through the entire thickness of the filter media. Alternatively, the openings may extend over a portion of the thickness of the filter media.

In some embodiments, the system also includes an additional filter media coupled to the filter media. In one such embodiment, the flow subsystem is configured to exert a force on the microspheres through the additional filter media. In one embodiment, the microspheres are contacted with the solution when the microspheres are positioned over the openings. In a different embodiment, the microspheres are not in contact with the solution when the microspheres are positioned over the openings.

In another embodiment, the system includes an imaging subsystem. The imaging subsystem is configured to image the microspheres as they are positioned over the openings. In one such embodiment, the surface of the filter media in contact with the microspheres is proximate to the imaging plane of the imaging subsystem. In another such embodiment, the surface of the filter media in contact with the microspheres is substantially parallel to the imaging plane of the imaging subsystem.

In some embodiments, the imaging subsystem is configured to image the microspheres through the filter media when the microspheres are positioned over the openings. In another embodiment, the imaging subsystem is configured to image the microspheres with multiple exposures when the microspheres are positioned over the openings. In an additional embodiment, the imaging subsystem includes a Charge Coupled Device (CCD). Alternatively, the imaging subsystem may include any other suitable imaging device or detector known in the art. In yet another embodiment, the images generated by the imaging subsystem may be used for pellet-based or cell-based diagnostic testing. Each of the embodiments of the system described above may be further configured as described herein.

Another embodiment relates to a method for positioning microspheres for imaging. The method includes applying a force to the microspheres through the filter media to position the microspheres over the openings in the filter media. The openings are spaced approximately equidistant across the filter media.

In one embodiment, the application of force is performed using suction-assisted filtration. The diameter of the opening may be smaller than the diameter of the microsphere. In addition, the diameter of the openings may also be larger than the diameter of the pores of the filter medium. The number of openings in the filter media may be approximately equal to the number of microspheres to be positioned. These openings may extend through the entire thickness of the filter media. Alternatively, the openings may extend over a portion of the thickness of the filter media.

Applying a force to the microspheres may also include applying a force to the microspheres through an additional filter media coupled to the filter media. When the microspheres are positioned over the openings, the microspheres may be contacted with a solution. Alternatively, the microspheres may not be in contact with the solution when the microspheres are positioned over the openings.

In some embodiments, the method also includes imaging the microsphere while the microsphere is positioned over the opening. In one such embodiment, the surface of the filter media in contact with the microspheres is proximate to the imaging plane. In another such embodiment, the surface of the filter media in contact with the microspheres is substantially parallel to the imaging plane.

In some embodiments, the method includes imaging the microspheres through the filter media while the microspheres are positioned over the openings. In another embodiment, the method includes imaging the microsphere with multiple exposures while the microsphere is positioned over the opening. In an additional embodiment, the method includes imaging the microspheres while positioned over the openings, and images generated by such imaging can be used for bead-based or cell-based diagnostic tests. Each of the above embodiments may include any other steps described herein.

Drawings

Other objects and advantages of the present invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:

FIG. 1 is a schematic diagram illustrating a cross-sectional view of a portion of one embodiment of a system configured to position microspheres for imaging;

FIG. 2 is a schematic diagram illustrating a top view of a portion of one embodiment of a system configured to position microspheres for imaging;

FIG. 3 is a schematic diagram illustrating a cross-sectional view of a portion of one embodiment of a system configured to position microspheres for imaging;

FIG. 4 is a schematic diagram illustrating a top view of a portion of one embodiment of a system configured to position microspheres for imaging; and

5-8 are schematic diagrams illustrating top views of portions of different embodiments of systems configured to position microspheres for imaging.

While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that: the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.

Detailed Description

The following description generally relates to methods and systems for immobilizing "microparticles" contained in a solution for purposes of illumination and imaging. The terms "microparticle" and "particle" are used interchangeably herein. In addition, the terms "microparticle" and "microsphere" are used interchangeably herein. The microparticles may comprise any discrete substance such as microspheres, cells, or composite polymers.

According to one method, a solution containing particles is provided to a holding material contained at the bottom of a vessel (e.g., a filter plate) suitable for suction-assisted filtration. Once the solution has been filtered of the fixing material and any additional or remaining solution has been removed, the particles are ready for imaging or illumination.

Thus, according to one embodiment, a system configured to position microspheres for imaging includes a filter media and a flow subsystem coupled to the filter media. The filter media includes an opening. The flow subsystem is configured to apply a force to the microspheres such that the microspheres are positioned over the openings. The flow subsystem may be configured to apply force via suction-assisted filtration.

Referring now to the drawings, note that: FIGS. 1-8 are not drawn to scale. In particular, the proportions of some of the elements of the drawings have been exaggerated strongly to emphasize their characteristics. Also note that: figures 1-8 are not drawn to the same scale. Similarly configurable elements shown in more than one figure have been indicated with the same reference numerals.

The immobilization materials described herein may include a pattern of specially designed holes in the microfiltration medium. In other words, the specifically designed pattern of perforation has one or more characteristics, such as spacing and transverse dimensions, that differ from one or more characteristics of the pores in the filter media. One or more characteristics of the aperture arrangement map may be selected based on one or more characteristics of the microsphere and one or more characteristics of the imaging subsystem. For example, the lateral dimension (e.g., diameter) of the apertures may be selected based on the lateral dimension (e.g., diameter) of the microspheres, and the spacing between the apertures may be selected based on one or more characteristics of the imaging subsystem, such as the angle of incidence and the angle of acquisition. The terms "aperture" and "opening" are used interchangeably herein.

As shown in FIG. 1, in one embodiment, filter media 10 includes openings 12. The holding material may be constructed by combining two layers of filter plate material-filter media 10 and additional filter media 14 coupled to filter media 10. The filter media 10 and 14 may be made of any suitable material known in the art. In addition, the filter media 10 and 14 may be made of the same or different materials. In addition, filter media 10 and 14 may have any suitable dimensions.

The filter medium 10 includes perforations that are in direct contact with the solution 11, while the second filter medium 14 may not be perforated. As shown in fig. 1, the layers will act together to form a well in which the particles can be substantially immobilized. For example, a flow subsystem (not shown in fig. 1) may be configured to apply a force to the microspheres 16 through the filter media 10 and the additional filter media 14, thereby positioning the microspheres 16 over the openings 12 in the filter media 10. The diameter of the opening 12 is preferably smaller than the diameter of the microsphere 16. In this way, the microspheres 16 will not slide completely into the openings and therefore will not be disposed within the openings 12 during imaging.

As shown in FIG. 1, the openings 12 may extend through the entire thickness of the filter media 10. Alternatively, the openings 12 may extend over only a portion of the filter media. Such an opening may be selected, for example, if additional filter media 14 is not coupled to filter media 10. The embodiment of the system shown in fig. 1 may be further configured as described herein.

The hole-to-hole spacing of the perforation alignment pattern is preferably large enough to allow illumination and imaging of individual particles and small enough for the particles to be included in the flow path of the positioning well. The arrangement preferably allows for equidistant particle positioning, as shown in fig. 2. Thus, as shown in FIG. 2, the openings 12 are spaced apart in a substantially equidistant pattern across the filter media 10. Filter media having random particulate fixing wells are also currently available. However, such currently available filter media do not contribute to the ideal equidistant particle distribution during particle imaging.

In one embodiment, the number of openings in filter media 10 is approximately equal to the number of microspheres to be positioned. In this manner, substantially all of the microspheres in a population or sample may be immobilized on filter media 10 for imaging. In another embodiment, the number of openings in the filter media is greater than or less than the number of microspheres. Thus, in one such embodiment, not all of the particles in a population or sample are located on the filter media. In some examples, a majority of the particles in a population or a sample will be located on the filter media.

As shown in fig. 2, the openings and microspheres may have a generally circular cross-sectional shape. However, the openings and microspheres may have any shape known in the art. Thus, if the openings and/or microspheres have a non-circular cross-sectional shape, the term "diameter" as used herein may be replaced with the term "cross-sectional transverse dimension". The embodiment of the system shown in fig. 2 may be further configured as described herein.

The distance between the individual openings, and thus the distance between the individual immobilized microspheres, may be selected to allow illumination and imaging of the immobilized microspheres. For example, as shown in FIG. 3, after vacuum 18 is applied to the microspheres 16 and solution 20, the microspheres 16 will be disposed over the openings 12 in the filter media 10. The microspheres are preferably spaced apart so that illumination 22 can be directed to each immobilized microsphere by the imaging subsystem 23 and light 24 returned from the microsphere as a result of the illumination can be collected and imaged by the imaging subsystem 23. The imaging subsystem 23 may be further configured as described herein.

Thus, as shown in FIG. 3, when the microspheres 16 are positioned over the openings, the microspheres may be contacted with the solution 20. However, when microspheres 16 are positioned over openings 12, the microspheres may not be in contact with solution 20. For example, after the microspheres are immobilized, the solution can be drained as described herein. For example, if the solution would interfere with the imaging of the microspheres, then draining of such solution may be performed. However, it should be understood that: although the solution may be drained, a relatively small amount of solution may still be present in the vicinity of the microspheres (e.g., a small amount of solution may be present on the surface of the microspheres).

The illumination may comprise light having any suitable wavelength known in the art. For example, if a fluorescent image of the microspheres is desired, the wavelength of the illumination may be selected such that the illumination causes one or more materials coupled to the microspheres to fluoresce. Alternatively, if a non-fluorescent image of the microspheres is desired, the wavelength of the illumination may be selected, for example, to optimize the image quality of the microsphere image. Illumination may also include monochromatic light, near-monochromatic light, polychromatic light, broadband light, coherent light, incoherent light, ultraviolet light, visible light, infrared light, or some combination of these. As shown in fig. 3, illumination may be directed at the microspheres at an oblique angle. Alternatively, the illumination may be directed at the microsphere at any other suitable angle of illumination (e.g., at right angle incidence). Illumination may be provided by a light source (not shown), such as a laser, light emitting diode, or any other suitable light source known in the art.

Light 24 returning from the microspheres as a result of illumination 22 may be collected by one or more optical elements (not shown), such as lenses or mirrors. The collected light may be detected by a suitable detector (not shown). For example, the collected light may be detected by a Charge Coupled Device (CCD), or any other imaging device or detector having a two-dimensional lattice of photosensitive elements, such as a Time Delay Integration (TDI) camera. Both illumination and light collection as well as detection may be performed by an imaging subsystem 23 included in the system. In addition to the optical elements and configurations described above, the imaging subsystem 23 may have any other optical configuration or include any suitable optical elements known in the art. The embodiment of the system shown in fig. 3 may be further configured as described herein.

As shown in fig. 4, the holes or perforations are preferably sufficiently larger than the pores of the filter medium. In other words, the diameter of the openings 12 is larger than the diameter of the pores 26 of the filter medium 10. As shown in fig. 3, the size of the apertures and the depth of the layer may be selected to immobilize the particles while maintaining sufficient exposure of the particle surface area for illumination and imaging. In addition, the pore size of the upper and lower filter media layers may be different in order to optimize the microsphere positioning process.

The microparticles used in the methods and systems described herein may have a minimum size limit related to the size of the pores. For example, for any given filter media, the particle size is preferably large enough so that the immobilized particles are not completely disposed (do not completely slide down) within the opening, which would otherwise complicate illumination and imaging.

Imaging may be performed after the microspheres have been immobilized, but while applying a force (e.g., a vacuum) to the microspheres. Alternatively, if the microspheres will remain relatively fixed in position after the force is removed, the force can be removed from the microspheres and imaging can then be performed. The embodiment of the system shown in fig. 4 may be further configured as described herein.

As shown in fig. 5, the immobilization of the microspheres forms an imaging plane 28. The system may also include an imaging subsystem (not shown in fig. 5) that may be configured as described above. In particular, the imaging subsystem is configured to image the microspheres as they are positioned over the openings. Thus, the surface 30 of the filter media 10 in contact with the microspheres is proximate to the imaging plane 28 of the imaging subsystem. Likewise, the microspheres will be near the imaging surface of the imaging subsystem. As shown in fig. 5, the imaging surface of the imaging subsystem may be positioned near the center of the microsphere. However, the imaging plane may also be positioned near the upper portion of the microspheres or near the portion of the microspheres that are in contact with the surface 30 of the filter media 10.

Additionally, as shown in FIG. 5, the surface 30 of the filter media 10 may be substantially parallel to the imaging plane 28 of the imaging subsystem. Thus, regardless of the location of the microspheres on the filter media, the microspheres will be located at approximately the same position relative to the imaging plane. Also, the systems and methods described herein will provide proper focusing of the imaging subsystem substantially throughout the filter media. Thus, no focus adjustment may be necessary between imaging of different microspheres. The embodiment of the system shown in fig. 5 may be further configured as described herein.

If the fixation material is transparent, imaging detection and/or illumination may be performed from either side of the fixation material. In other words, an imaging subsystem, which may be configured as described above, may be configured to image the microspheres through the filter media when the microspheres are positioned over the openings.

In one embodiment, as shown in FIG. 6, a solution 20 containing particles 16 is provided to a fixation material 10 in a container 32. The container 32 may have any suitable configuration known in the art. When vacuum 18 is applied to the bottom of the composite filter media (i.e., the bottom of the additional filter media 14 coupled to the filter media 10), solution flow 34 is created due to the lower restriction of the bottom of the well 32 (i.e., the portion of the well 32 near the filter media 10) and the applied vacuum 18. Vacuum 18 may be created using a fluid subsystem 33 coupled to the container by tubing 35. The fluid subsystem 33 may be configured as described herein. The conduit 35 may comprise any suitable conduit known in the art. The particles contained in the solution stream are positioned and immobilized on the open pore region 12 until such time as most of the wells included in the arrangement are filled with particles, as shown in FIG. 6. The system may also include a subsystem (not shown) such as a vibration device configured to facilitate movement of the particulates into the well. The embodiment of the system shown in fig. 6 may be further configured as described herein.

In contrast to the double layer filter media described above, another fixed media configuration includes a single open pore filter media layer or filter media 36 that can be used to contain or hold particles 16 of a particular size, as shown in FIG. 7. The single layer may be made of a filter plate material that is thicker than the filter media 10 to provide sufficient mechanical stability to the filter media. The filter media 36 may be made of any suitable material known in the art. The filter media 36 and the openings 44 therein may be formed using any process known in the art. The immobilization of the microspheres on the filter media 36 may be performed in a similar manner as described above. For example, a vacuum 38 may be applied to a side 40 of the filter medium 36, thereby "pulling" a solution 42 having the particulates 16 disposed therein through an opening 44 in the filter medium 36 and securing the particulates 16 to the opening 44. The opening 44 and filter media 36 may be further configured as described above. The embodiment of the system shown in fig. 7 may be further configured as described herein.

Another configuration is an open pore solid substrate 46 which may be used to hold particles 48 so that the majority of the pore pattern or openings 50 are filled with particles, as shown in fig. 8. The microparticles 48 may be immobilized as described above. For example, a vacuum 52 may be applied to a side 54 of substrate 46, thereby "pulling" solution 56 through opening 50 and immobilizing particles 48 on a side 58 of substrate 46. The solution 60 may be contacted with the immobilized microparticles. Once the pores have been "filled" with microspheres, the solution does not run off. Any remaining solution 60 may be drained by another means such as described above. Solid substrate 46 and opening 50 therein may be formed using any suitable material and process known in the art. The embodiment of the system shown in fig. 8 may be further configured as described herein.

Any remaining solution containing the particles may be drained by another means, such as siphoning or vacuum treatment, or the fixing material may be rotated to allow any remaining particles to settle out of the alignment pattern formed in the fixing material. The discharge of the solution containing unfixed particles may be performed with or without maintaining suction on the bottom of the fixing material. The number of particles in the solution can be selected based on the number of pores in the alignment chart formed by the fixing material. For example, in one embodiment, the number of openings in the filter media may be approximately equal to the number of microspheres in the solution.

Imaging particles may be accomplished without particles in solution. The particles preferably lie in a plane that is substantially equidistant from the imaging subsystem or imaging device. For long exposures or multiple exposures, a fix may be required. Because the systems and methods described herein provide for substantially stable immobilization of the microspheres, the imaging subsystem may be configured to image the microspheres with multiple exposures as the position of the microspheres will be substantially stable over the extended imaging time required for the multiple exposures when the microspheres are positioned over the openings. Thus, the systems and methods described herein may provide greater flexibility in the variety of microsphere images formed. In addition, multiple exposures may provide more information about the microspheres than a single exposure.

The images of the microspheres may be used in bead-based or cell-based diagnostic tests, which may include any such tests known in the art. Examples of such diagnostic tests are described in U.S. Pat. Nos. 5,981,180 to Chandler et al, 6,046,807, 6,319,800, 6,366,354B1, 6,411,904B1 to Chandler et al, and 6,449,562B1 and 6,524,793B1 to Chandler et al, which are incorporated by reference in their entirety for all purposes. The assays and tests in which images of microspheres described herein can be used include any of those described in these patents, as well as any other assays and tests known in the art.

Another embodiment relates to a method for positioning microspheres for imaging. The method includes applying a force to the microspheres through the filter media such that the microspheres are positioned over the openings in the filter media. The openings are spaced approximately equidistant across the filter media.

In one embodiment, the application of force is performed using suction-assisted filtration. The diameter of the openings of these may be smaller than the diameter of the microspheres. The diameter of these openings may also be larger than the diameter of the pores of the filter medium. The number of openings in the filter media may be approximately equal to the number of microspheres. These openings may extend through the entire thickness of the filter media. Alternatively, the openings may extend over a portion of the thickness of the filter media.

Applying a force to the microspheres includes applying a force to the microspheres through an additional filter media coupled to the filter media. When the microspheres are positioned over the openings, the microspheres may be contacted with a solution. Alternatively, the microspheres may not be in contact with the solution when the microspheres are positioned over the openings.

In some embodiments, the method includes imaging the microsphere while the microsphere is positioned over the opening. In one such embodiment, the surface of the filter media in contact with the microspheres is proximate to the imaging plane. In another such embodiment, the surface of the filter media in contact with the microspheres is substantially parallel to the imaging plane.

In some embodiments, the method includes imaging the microspheres through the filter media while the microspheres are positioned over the openings. In another embodiment, the method includes imaging the microsphere with multiple exposures while the microsphere is positioned over the opening. In an additional embodiment, the method includes imaging the microsphere while positioned over the opening, and images generated by the imaging can be used for bead-based or cell-based diagnostic tests. Each of the above embodiments may include any other steps described herein.

Persons of ordinary skill in the art having benefit of the present disclosure should appreciate that: the present invention is believed to provide methods and systems for positioning microspheres for imaging. Further variations and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It should be understood that: the forms of the invention herein shown and described are to be taken as the presently preferred embodiments. Various elements and materials may be substituted for those shown and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims.

The claims (modification according to treaty clause 19)

1. A system configured to position microspheres for imaging, comprising:

a filter media comprising a plurality of openings; and

a flow subsystem coupled to the filter media, wherein the flow subsystem is configured to apply a force to microspheres such that the microspheres are positioned over the openings.

2. The system of claim 1, wherein the flow subsystem is further configured to apply the force via suction-assisted filtration.

3. The system of claim 1, wherein the opening has a diameter smaller than a diameter of the microsphere.

4. The system of claim 1, wherein the opening has a diameter larger than a diameter of the pores of the filter media.

5. The system of claim 1, wherein the filter media further comprises a plurality of the openings such that the microspheres are dispersed on a surface substantially parallel to an imaging plane.

(deletion)

7. The system of claim 1, wherein the opening extends through the thickness of the filter media.

8. The system of claim 1, wherein the opening extends over a portion of a thickness of the filter media.

9. The system of claim 1, further comprising an additional filter media coupled to the filter media, wherein the flow subsystem is further configured to apply the force to the microspheres through the additional filter media.

10. The system of claim 1, wherein the immobilized microspheres are contacted with a solution.

11. The system of claim 1, wherein the immobilized microspheres are not in contact with a solution.

12. The system of claim 1, further comprising an imaging subsystem configured to image the microspheres when the microspheres are positioned over the openings, wherein a surface of the filter medium in contact with the microspheres is proximate an imaging plane of the imaging subsystem.

13. The system of claim 1, further comprising an imaging subsystem configured to image the microspheres when the microspheres are positioned over the openings, wherein a surface of the filter medium in contact with the microspheres is substantially parallel to an imaging plane of the imaging subsystem.

14. The system of claim 1, further comprising an imaging subsystem configured to image the microspheres through the filter media when the microspheres are positioned over the openings.

15. The system of claim 1, further comprising an imaging subsystem configured to image the microspheres using multiple exposures when the microspheres are positioned over the openings.

16. The system of claim 1, further comprising an imaging subsystem configured to image the microsphere when the microsphere is positioned over the opening, wherein the imaging subsystem comprises a charge-coupled device.

17. The system of claim 1, further comprising an imaging subsystem configured to image the microsphere when the microsphere is positioned over the opening, wherein the imaging subsystem comprises an imaging device.

18. The system of claim 1, further comprising an imaging subsystem configured to image the microspheres as they are positioned over the openings, wherein images generated by the imaging subsystem may be used for pellet-based or cell-based diagnostic tests.

19. A method for positioning microspheres for imaging comprising applying a force to the microspheres through a filter media such that the microspheres are positioned over openings in the filter media.

20. The method of claim 19, wherein the applying is performed by using suction-assisted filtration.

21. The method of claim 19, wherein the opening has a diameter smaller than a diameter of the microsphere.

22. The method of claim 19, wherein the openings have a diameter larger than a diameter of the pores of the filter media.

23. The method of claim 19, wherein the number of openings in the filter media is approximately equal to the number of microspheres.

24. The method of claim 19, wherein the openings extend through the thickness of the filter media.

25. The method of claim 19, wherein the opening extends over a portion of the thickness of the filter media.

26. The method of claim 19, wherein said applying comprises applying said force to said microspheres through an additional filter media coupled to said filter media.

27. The method of claim 19, wherein the microspheres are contacted with a solution while the microspheres are positioned over the openings.

28. The method of claim 19, wherein the microspheres are not in contact with the solution when the microspheres are positioned over the openings.

29. The method of claim 19, further comprising imaging the microspheres as they are positioned over the openings, wherein a surface of the filter medium in contact with the microspheres is proximate to an imaging plane.

30. The method of claim 19, further comprising imaging the microspheres while the microspheres are positioned over the openings, wherein a surface of the filter medium in contact with the microspheres is substantially parallel to an imaging plane.

31. The method of claim 19, further comprising imaging the microspheres through the filter media while the microspheres are positioned over the openings.

32. The method of claim 19, further comprising imaging the microsphere using multiple exposures while the microsphere is positioned over the opening.

33. The method of claim 19, further comprising imaging the microsphere while the microsphere is positioned over the opening, wherein an image generated by the imaging can be used for a bead-based or cell-based diagnostic test.

Claims (33)

1. A system configured to position microspheres for imaging, comprising:

a filter media comprising a plurality of openings spaced apart in a substantially equidistant pattern on said filter media; and

a flow subsystem coupled to the filter media, wherein the flow subsystem is configured to apply a force to microspheres such that the microspheres are positioned over the openings.

2. The system of claim 1, wherein the flow subsystem is further configured to apply the force via suction-assisted filtration.

3. The system of claim 1, wherein the opening has a diameter smaller than a diameter of the microsphere.

4. The system of claim 1, wherein the opening has a diameter larger than a diameter of the pores of the filter media.

5. The system of claim 1, wherein the number of openings in the filter media is approximately equal to the number of microspheres to be positioned.

6. The system of claim 1, wherein the number of openings in the filter media is greater or less than the number of microspheres.

7. The system of claim 1, wherein the opening extends through the thickness of the filter media.

8. The system of claim 1, wherein the opening extends over a portion of a thickness of the filter media.

9. The system of claim 1, further comprising an additional filter media coupled to the filter media, wherein the flow subsystem is further configured to apply the force to the microspheres through the additional filter media.

10. The system of claim 1, wherein the microspheres are contacted with a solution when the microspheres are positioned over the opening.

11. The system of claim 1, wherein the microspheres are not in contact with the solution when the microspheres are positioned over the opening.

12. The system of claim 1, further comprising an imaging subsystem configured to image the microspheres when the microspheres are positioned over the openings, wherein a surface of the filter medium in contact with the microspheres is proximate an imaging plane of the imaging subsystem.

13. The system of claim 1, further comprising an imaging subsystem configured to image the microspheres when the microspheres are positioned over the openings, wherein a surface of the filter medium in contact with the microspheres is substantially parallel to an imaging plane of the imaging subsystem.

14. The system of claim 1, further comprising an imaging subsystem configured to image the microspheres through the filter media when the microspheres are positioned over the openings.

15. The system of claim 1, further comprising an imaging subsystem configured to image the microspheres using multiple exposures when the microspheres are positioned over the openings.

16. The system of claim 1, further comprising an imaging subsystem configured to image the microsphere when the microsphere is positioned over the opening, wherein the imaging subsystem comprises a charge-coupled device.

17. The system of claim 1, further comprising an imaging subsystem configured to image the microsphere when the microsphere is positioned over the opening, wherein the imaging subsystem comprises an imaging device.

18. The system of claim 1, further comprising an imaging subsystem configured to image the microspheres as they are positioned over the openings, wherein images generated by the imaging subsystem may be used for pellet-based or cell-based diagnostic tests.

19. A method for positioning microspheres for imaging comprising applying a force to the microspheres through a filter media such that the microspheres are positioned over openings in the filter media, wherein the openings are spaced approximately equidistant across the filter media.

20. The method of claim 19, wherein the applying is performed by using suction-assisted filtration.

21. The method of claim 19, wherein the opening has a diameter smaller than a diameter of the microsphere.

22. The method of claim 19, wherein the openings have a diameter larger than a diameter of the pores of the filter media.

23. The method of claim 19, wherein the number of openings in the filter media is approximately equal to the number of microspheres.

24. The method of claim 19, wherein the openings extend through the thickness of the filter media.

25. The method of claim 19, wherein the opening extends over a portion of the thickness of the filter media.

26. The method of claim 19, wherein said applying comprises applying said force to said microspheres through an additional filter media coupled to said filter media.

27. The method of claim 19, wherein the microspheres are contacted with a solution while the microspheres are positioned over the openings.

28. The method of claim 19, wherein the microspheres are not in contact with the solution when the microspheres are positioned over the openings.

29. The method of claim 19, further comprising imaging the microspheres as they are positioned over the openings, wherein a surface of the filter medium in contact with the microspheres is proximate to an imaging plane.

30. The method of claim 19, further comprising imaging the microspheres while the microspheres are positioned over the openings, wherein a surface of the filter medium in contact with the microspheres is substantially parallel to an imaging plane.

31. The method of claim 19, further comprising imaging the microspheres through the filter media while the microspheres are positioned over the openings.

32. The method of claim 19, further comprising imaging the microsphere using multiple exposures while the microsphere is positioned over the opening.

33. The method of claim 19, further comprising imaging the microsphere while the microsphere is positioned over the opening, wherein an image generated by the imaging can be used for a bead-based or cell-based diagnostic test.