Patent Application
20050271553
There has been a desire in recent years to develop methods for purifying biochemical solutions and mixtures that contain target molecules or compounds and impurities. Various methods have been used purifying biological samples and include contacting a sample with an ion-exchange resin. There continues to be a need for fast and efficient methods and devices for purifying a biological sample.
According to various embodiments, an apparatus is provided having a petal-array of purification materials that can be disposed within respective wells of a multi-well microplate, for example, a standard-format 96- or 384-well plate. Methods of making and using the apparatus are also provided. The purification material can be located on an array of members, for example, petal-shaped purification members, adapted for insertion into a corresponding array of reaction wells. The purification members can also include binding sites for target components. An apparatus and method for facilitating the release of labeled monomers from a purification and binding support within a microplate format, are also provided.
According to various embodiments, an analyte-manipulation apparatus is provided. The apparatus can include, for example, a plurality of wells defining an array, wherein each of the wells includes a rim defining an opening at an upper end of each well, with the openings being disposed within a first plane. The apparatus can include a support, for example, a sheet, including a plurality of petal-shaped purification or ion-exchange members formed therein at positions corresponding to the wells of the array, with the support being disposed along a second plane above and substantially parallel to the first plane, and with at least one of the petal-shaped purification members being positioned near each one of the openings. According to various embodiments, the apparatus can include a stack of supports, for example, formed as individual sheets, disposed above the well openings, with each support of the stack including a plurality of petal-shaped purification members integrally formed therein, and with each petal-shaped purification member of each support being disposed at a position corresponding to a respective one of the wells of the array. The stack of supports can include more than one support, for example, at least three of the supports, for example, 3, 4, 5, 6, 7, 8, 9, 10, or more supports. Each of the petal-shaped purification members can be movable between (i) a first position, substantially within the second plane, and (ii) a second position, at least partially disposed outside of the second plane and extending at least partially into a nearby well via a respective opening. The apparatus can further include a platen including a major surface facing the support, and a plurality of ring-shaped projections extending outwardly from the major surface of the platen. The platen can be adapted for movement toward and away from the support, whereby upon moving the platen toward the support, the projections can pressingly engage the petal-shaped purification members, thereby deflecting the petal-shaped purification members from the first position to the second position. Each of the ring-shaped projections can taper in a direction away from the major surface.
According to various embodiments, the platen and each of the ring-shaped projections of the platen defines a passage extending longitudinally through each ring-shaped projection and through the platen. An instrument, for example, a pipette, can be inserted through the passage to access the interior region of any one or more of the wells when the petal-shaped purification members are deflected into their respective wells. For example, a sample and/or reagent can be deposited into or withdrawn from one or more selected wells by using an instrument via the passage.
According to various embodiments, the apparatus can further include a die plate disposed between the support and the plurality of wells, wherein the die plate includes an array of apertures extending therethrough, with each of the apertures being disposed at a position corresponding to a respective one of the wells of the array.
Additional features and advantages of various embodiments will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practice of various embodiments. The objectives and other advantages of various embodiments will be realized and attained by means of the elements and combinations particularly pointed out in the description below.
The present teachings can further be understood by reference to the following description taken in conjunction with the accompanying drawings, in which identical reference numerals identify identical or similar elements, and in which:
a illustrates several synthetic polymers that can be included in the coating for the polyelectrolyte-coated particle.
a-9d demonstrate separation of sequencing reaction products with polyelectrolyte-coated particles with biopolymer in comparison with standard separation techniques, where
a-10b demonstrate separation of PCR reaction products by polyelectrolyte-coated particles with biopolymer, where
a-11b is a set of graphs illustrating a detail of
a-13b demonstrate separation of a sequencing reaction products with polyelectrolyte-coated particles synthetic polymer;
a and 15b demonstrate the separation of sequencing reaction products by polyelectrolyte-coated particles with synthetic polymer;
According to various embodiments, methods of providing an array of solid supports or binding sites within wells of a microplate, for example, a standard-format 96- or 384-well plate, are provided. Also provided are methods for facilitating the release of species, for example, labeled monomers, from one or more support, wherein the one or more support can be in a microplate format.
According to various embodiments, and with initial reference to
The support sheets 12a-h can be formed of any suitable material, for example, a membrane or film material. According to various embodiments, each of the support sheets 12a-h independently can include a polymeric film, for example, a polycarbonate or polystyrene film, having a thickness of between about 0.001 inch and about 0.010 inch, for example, about 0.004 inch. The film can be textured to increase its effective surface area. According to various embodiments, each support sheet can be a die-cut, chemically-treated, membrane or film support.
Each of the support sheets 12a-h can include one or more location features to facilitate alignment with respect to other system components. For example, as shown in FIGS. 2 and 3, slots 22 can be formed at selected locations along the edge regions of each of the support sheets 12a-h. The slots 22 can be positioned and configured to mate with complementary-shaped regions of one or more of the microplate 18, die plate 14, and platen 16. For example,
According to various embodiments, all the petal-shaped purification members of any one of the supports can face, or “point,” in the same direction. The directionality of the petal-shaped purification members can differ between any two of the supports. That is, the petal-shaped purification members of any one support can point in a direction that differs from that of any of the other supports. In the embodiment of
According to various embodiments, each of the petal-shaped purification members 21a-h can be deformable from a normal position, substantially within a plane defined by the sheet, to a second position, at least partially disposed outside of such plane. The petal-shaped purification members can be resilient such that they return to their normal position after a deforming force in discontinued. Due to the deformable quality of the petal-shaped purification members, applying a downwardly-directed force against a petal-shaped purification member can deflect the member from its normal position to a second position, for example, below the plane of the support. Upon removing the force, the resilient petal-shaped purification member can return substantially to its normal position.
As shown in
The die plate 14, platen 16, and microplate 18 can be formed by any conventional means, for example, by injection molding. According to various embodiments, these components can be constructed of any substantially rigid, water-insoluble, fluid-impervious material that is substantially chemically non-reactive with materials, for example, biochemicals, samples, reagents, and the like, intended for use therewith. The term “substantially rigid” as used herein is intended to mean that the material will resist deformation or warping under a light mechanical or thermal load, although the material may be somewhat elastic. Suitable materials can include, but are not limited to, acrylics, polycarbonates, polypropylenes, and polysulfones.
According to various embodiments, microplate 18 can be an injection molded plastic plate, the length and width of which conform to a commonly used standard, for example, a rectangle of 5.03 inches×3.37 inches (127.8 mm by 85.5 mm). In the illustrated embodiments, wells are formed integrally with the microplate, and can be arranged, for example, in a 12×8 regular rectangular array and spaced 0.9 cm center-to-center. Although the illustrated embodiments show arrangements configured in accordance with the popular 96-well format, the present teachings also contemplate any other number of wells, for example, 12, 24, 48, 192, or 384 wells, laid out in any suitable configuration, for example, square, rectangular, circular, ovoid, or other regular or irregular patterns.
In operation, a die plate 14 can be positioned over a multi-well microplate 18, with each aperture 30 of the die plate 14 located over a corresponding one of the wells of the microplate 18. A plurality of support sheets 12 can be stacked upon the die plate. Alignment of the support sheets 12 with respect to the die plate 14 can be facilitated by way of slots 22 formed in the support sheets 12 and mating projections 26 extending from a surface of the die plate 14 facing the support sheets 12. Each support sheet 12 of the stack can include a plurality of petal-shaped purification members 21, with each petal-shaped purification member 21 of each support sheet 12 being disposed at a position corresponding to a respective one of the wells of the microplate 18. Each of the petal-shaped purification members 21 can be moved between (i) a first position, outside of a corresponding well, and (ii) a second position, extending at least partially into the corresponding well. A platen 16 can be placed over the stack of support sheets 12. The platen 16 can include a major surface 16a facing the support sheets 12, and a plurality of ring-shaped projections 36 can extend outwardly from the major surface 16a toward the support sheets 12. The platen 16 can be moved toward and away from the support sheets 12. Upon moving the platen 16 toward the support sheets 12, the projections 36 can pressingly engage the petal-shaped purification members 21, thereby deflecting the petal-shaped purification members 21 from the first to the second position, as depicted in
According to various embodiments, one or more chemicals, biochemicals, or purification medium can be present on at least a portion of one or more of the petal-shaped purification members. The petal-shaped purification members can be introduced into respective wells that can contain a first sample, such as a polymerized chain reaction product or DNA sequencing product. The chemicals, biochemicals, and/or purification medium on the petal-shaped purification members can interact with the first sample to bind one or more components of the sample. The chemicals, biochemicals, and/or purification medium on the petal-shaped purification members can bind desirable components, for example, DNA fragments, dsDNA, ssDNA, polynucleotides, oligonucleotides, and the like. Alternately, the chemicals, biochemicals, and/or purification medium on the petal-shaped purification members can bind undesirable reaction products, including fragments, salts, promoters, terminators, reactive dyes, and other undesirable reaction products as known to those of ordinary skill in the art. According to various embodiments, one or more nucleic acids can be purified by and/or immobilized on the petal-shaped purification members. The petal-shaped purification members can be introduced into respective wells that can contain reagents for carrying out polymerase chain reaction (PCR). PCR can then be carried out in the wells. Analysis of the PCR product(s) can then be performed.
According to various embodiments, at least a portion of the petal-shaped purification members can be chemically treated. One or more of the petal-shaped purification members can include one or more biochemicals immobilized thereon. Such biochemicals can include, for example, one or more nucleic acids. In various embodiments, such biochemicals can include one or more DNA-sequencing reagents, such as terminators, primers, or a combination thereof. At least a portion of the petal-shaped purification members can have a purification medium, for example, size-exclusion ion-exchange particles, ion-exchange particles, a size-exclusion resin, or a combination thereof, affixed thereto.
According to various embodiments, the coated ion-exchange resins can be affixed to the petal-shaped purification members to provide a device to hold the resin after purification is complete so that the purified liquid can be collected while leaving the resin affixed to the purification member. The resin can be affixed with a variety of processes known in the art including adhesives, sintering, coating, etc.
The term “particle” as used herein refers to an ion-exchange material of liquid, solid, and/or gas that can be coated. The coating can cover the entire exterior surface of the particle or substantial portions thereof. The coating can cover portions of the interior surfaces of the particle. The coating can be irreversible to permanently coat the particle, or reversible to release the particle upon dissolution of the coating. The particle can be a single material or an agglomerate of materials that can be prepared by, for example, fusion, sintering, pressing, compressing, phase separation, precipitation, aggregation and coalescence, or otherwise formed together. The particle can have any shape either regular or irregular such as spherical, elliptical, triangular, cylindrical, etc.
The term “material” as used herein refers to any substance on a molecular level or in bulk and can be a liquid and/or solid, e.g. an emulsion or a resin.
The term “pore size” as used herein refers to a mean measurement, providing a guideline that particles larger than the pore size are less likely to penetrate into the interior of the particle, while smaller particles are more likely to penetrate into the interior of the particle. It is to be understood that the particles admitted to or deflected from a pore are not necessarily exactly the “pore size” given. That is, admittance to or exclusion from the pore is based on many factors, including actual pore size (wherein each pore of a core can have a different size), steric hindrance factors, ionic attractions, polarizations, and the like. Additionally, some particles, such as microporous gel type ion exchange materials, do not have defined pores. The particles have a “pore size that is defined by the intermolecular spacing within the gel matrix to define the size exclusion limit.
The term “ion-exchange” as used herein refers to the process wherein each charge equivalent that can be “coupled” or “captured” on the ion-exchange surface can release an equivalent charge into an appropriate solution. This displacement of counter-ions from the ion-exchange core can release a large number of counter-ions into a sample solution. The selectivity of the ion-exchange core can be greater for the ion to be removed from the sample solution than for the counter-ion of the ion-exchange core. Ions of similar affinity as the counter-ion establish an equilibrium distribution based on the relative affinity of the ions for the ion-exchanger. The equilibrium can either provide or not provide the uptake of ions from solution. The counter-ion can be almost any ion including chloride, hydroxide, acetate, formate, bromide, sulfate, nitrate, phosphate or any other organic or inorganic anion. The choice of counter-ion can be influenced by the nature of the ions in solution that are to be removed. A counter-ion can be selected that has a significantly lower affinity for the ion-exchange core relative to the ion in solution, thus providing exchange with the ion in solution. Neutralization using a cation exchange resin in a mixed bed can drive the uptake of an ion from solution. This can be the case even if the affinity of the cation for the resin is lower than the affinity for the counter-ion. While the above describes the use of anion-exchange particles, the present teachings are analogous for cation-exchange particles. Counter-ions for cation-exchange particles include hydronium, sodium, potassium, ammonium, calcium, magnesium, or any other organic or inorganic cation. Polyelectrolyte-coated ion-exchange particles can be prepared in any ionic form.
The term “mixture” as used herein refers to more than one polyelectrolyte-coated particle used together in a packed column, a mixed-bed, a homogenous bed, a fluidized bed, a static column with continuous flow, or a batch mixture, for example. The mixture can include polyelectrolyte-coated cation-exchange particles, polyelectrolyte-coated anion-exchange particles, uncoated cation-exchange particles, uncoated anion-exchange particles, inerts, or any combination thereof. The mixture can include any physical configuration known in the art of separations, and any chemical mixture known in the art of ion exchange. The mixture can be any proportion including stoichiometric equivalent amounts. A mixture of particles can provide size-based removal with desalting of the solution. An example is a polyelectrolyte-coated ion-exchange particle in the hydroxide form in a mixed bed with cation-exchange particles in a hydronium form. A mixture of particles can provide size-based removal of small ions without desalting the solution. An example is a polyelectrolyte-coated ion-exchange particle in the chloride or acetate form (or any other anion other than hydroxide), and no cation exchange material. The choice of counter-ionic form used for the polyelectrolyte-coated ion-exchange particles can be based on the application for which they are to be implemented.
The term “coating” and grammatical variations thereof as used herein refer to less than a monolayer, a monolayer, or multiple layers of a polyelectrolyte with the same charge, or multiple layers of varied polyelectrolytes with opposite charges covering the particle. Smaller molecules, such as, for example, inorganic buffer ions, and nucleotides can penetrate or permeate through the coating and can be retained by or ion-exchanged with the particle. The coating can prevent larger molecules, such as, for example, nucleic acids, from penetrating or permeating through the coating and reacting with the particle.
The terms “polymer,” “polymerization,” “polymerize,” “cross-linked product,” “cross-linking,” “cross-link,” and other like terms as used herein are meant to include both polymerization products and methods, and cross-linked products and methods wherein the resultant product has a three-dimensional structure, as opposed to, for example, a linear polymer. The term “polymer” also refers to oligomers, homopolymers, and copolymers. Polymerization can be initiated thermally, photochemically, ionically, or by any other means known to those skilled in the art of polymer chemistry. According to various embodiments, the polymerization can be condensation (or step) polymerization, ring-opening polymerization, high energy electron-beam initiated polymerization, free-radical polymerization, including atomic-transfer radical addition (ATRA) polymerization, atomic-transfer radical polymerization (ATRP), reversible addition fragmentation chain transfer (RAFT) polymerization, or any other living free-radical polymerization.
The prefix “(meth)acryl” as used herein refers to methacryl and acryl. For example, N-methyl (meth)acrylamide refers to N-methyl methacrylamide and N-methyl acrylamide, and 2-hydroxyethyl (meth)acrylate refers to 2-hydroxyethyl methacrylate and 2-hydroxyethyl acrylate.
The term “DNA” as used herein refers to any nucleic acid, including RNA, PNA, and others as understood to one skilled in the art of molecular biology.
According to various embodiments, polyelectrolyte-coated particles can have many uses such as, for example, in the separation of biomolecules. According to various embodiments, polyelectrolyte-coated particles can provide separation of biomolecules by restricting the ability of large molecules to interact with ion-exchange active sites of the particle. Small molecules that can penetrate into the polyelectrolyte-coated particle can interact with the ion-exchange active sites and can be retained on those sites. Larger, highly charged species can be restricted from interacting with the ion-exchange core by the coating or by the pore size of the core particle. Such larger, highly charged species can remain in solution rather than bind to the ion-exchange particle. Larger species that remain in solution can be separated. Larger molecules are not immobilized on the coating. According to various embodiments, the small molecules can be eluted from polyelectrolyte-coated particles. According to various embodiments, large molecules can include single stranded DNA (ssDNA) fragments, and double stranded DNA (dsDNA) fragments, and small molecules can include nucleotides, short fragments of ssDNA, short fragments of dsDNA, and small ions such as chloride, acetate, and surfactants.
According to various embodiments, a polyelectrolyte-coated particle can be provided by exposing an ion-exchange core to an excess of polyelectrolyte. The core surface can become coated with the polyelectrolyte. The polyelectrolyte can be a biopolymer, including a naturally occurring biopolymer such as DNA, or a synthetic polymer as described herein.
According to various embodiments, a polyelectrolyte-coated particle can be provided by exposing an ion-exchange core to a polyelectrolyte containing charges opposite to that of the core. After the coating of the first polyelectrolyte, the coated particle is exposed to another polyelectrolyte containing charges opposite to that of the first polyelectrolyte. The coating process can be repeated to provide a polyelectrolyte-coated particle with multiple layers of alternative polyanion and polycation.
According to various embodiments, a coating including polyelectrolyte can decrease the interaction of large molecules, including ssDNA, with the core by a size sieving effect. The coating can cover the outer surface of an ion-exchange core, decreasing interaction of large molecules with the surface. The coating can create a size-exclusion barrier decreasing penetration of large molecules into the interior of the core particle. The chemical properties of the polyelectrolyte can determine the sieving properties that the polyelectrolyte-coated particle displays. Properties of the polyelectrolyte such as charge, charge density, hydrophobicity, tactility, flexibility, ratio of monomer units used in co- and ter-polymers, and molecular weight can all be modified in order to provide the desired sieving characteristics. According to various embodiments, the polyelectrolyte coating can be crosslinked in a later step to obtain desirable physical properties and size-exclusion characteristics.
According to various embodiments, a polyelectrolyte-coated particle can function as a size-excluded ion-exchanger by exploiting the inherent porosity of the ion-exchange core. Ion-exchange cores can be obtained with a wide variety of pore sizes, such as 5 angstroms (microporous) and 1000 angstroms or greater (macroporous). An ion-exchange core can be selected based on pore size such that it excludes molecules of a given size based on the requirements of the application. According to various embodiments, the polyelectrolyte coating can be large enough to be excluded from the pores of the ion-exchange core, thereby coating the exterior surface with substantially decreased coating of the interior of the pores. The polyelectrolyte coating can decrease the interaction of large molecules, such as ssDNA with the surface of the ion-exchange core by blocking a substantial amount of the surface ion-exchange sites. The pore size of the ion-exchange core bead can be small enough to decrease the penetration of large molecules, such as ssDNA, into the pores of the core and interacting with the core ion-exchange sites. According to various embodiments, the surface ion-exchange sites can be substantially blocked and the inner ion-exchange sites can become less accessible, such that the polyelectrolyte-coated particle retains significantly less large molecules, such as dsDNA. In contrast, smaller ions such as chloride, acetate, phosphate, pyrophosphate, small oligonucleotides, and nucleotides can enter the pores of the ion-exchange core and interact with interior ion-exchange sites. The coating can decrease the interaction of small ions, like the large molecules, with the surface ion-exchange sites because the surface sites are occupied by the polyelectrolyte coating. The resultant ion-exchange capacity of such a polyelectrolyte-coated particle (for small ions) is equal to the working capacity of the bare ion-exchange core minus the capacity of the surface of the core. The interior pores of the particle provide the substantial ion-exchange capacity of the polyelectrolyte-coated particle after the surface ion-exchange sites have been occupied by the polyelectrolyte coating.
According to various embodiments, a coating can be formed on an ion-exchange core such that the coating has a thickness of from less than an equivalent monolayer to multiple layers. The thickness of the coating can vary over the surface of the ion-exchange core, or the thickness of the coating can be uniform over the entire surface of the ion-exchange core. According to various embodiments, the coating can at least partially cover the ion-exchange core. The coating material can at least partially fill one or more pore or surface feature, for example, pores, cracks, crevices, pits, channels, holes, recesses, or grooves, of the ion-exchange core. For example, an ion-exchange core can be coated on all internal and external surfaces with a polyelectrolyte suitable for forming a coating.
According to various embodiments,
According to various embodiments, the ion-exchange core can be an anionic or cationic material. The ion-exchange core can be a polymer, cross-linked polymer, or inorganic material, for example, silica. The ion-exchange core can be a solid core material capable of ion-exchange, or a solid core material treated with an ion-exchange resin. The ion-exchange core can be surface-activated. The ion-exchange core can be non-magnetic, paramagnetic, or magnetic. Exemplary ion-exchange core materials include those listed below.
According to various embodiments, ion-exchange material for the core can include anion-exchange resins such as Macro-Prep High Q, Macro-Prep 25Q, Aminex A-27, AG 1-X2, AG 1-X4, AG 1-X8, and AG 2-X8 (Bio-Rad, Hercules, Calif., USA), Chromalite 30 SBG (Purolite Company, Bala Cynwyd, Pa., USA), POROS HQ 20 (Applied Biosystems, Framingham, Mass., USA), CA08Y and CA08S (Mitsubishi Chemical America, White Plains, N.Y., USA), Powdex PAO (Graver Technologies, Glasgow, Del., USA), Nucleosil SB (Alltech Associates, Inc., Deerfield, Ill., USA), Fractogel TMAE (EM Science, Gibbstown, N.J., USA), IE 1-X8 (Spectrum Chromatography, Houston, Tex., USA), Super Q-650S (TosoHaas Bioscience, Montgomeryville, Pa., USA), TMAHP-100 (Iontosorb AV, Czech Republic), Chromalite 30 SBA (Purolite International Ltd., UK), and ANEX-QS (Transgenomic, Inc., San Jose, Calif., USA). According to various embodiments, the cores material can include PMMA, PS-DVB, silica, and/or cellulose. According to various embodiments, ion-exchange cores can include cation-exchange resins provided by manufacturers similar to those for anion-exchange resins including Chromalite 30 SAG (Purolite International Ltd., UK), AG 50WX8 and Macro-Prep High S (Bio-Rad, Hercules, Calif., USA). Other cation and anion resins that can be used as ion-exchange cores will be apparent to one of ordinary skill in the art of ion-exchange resins.
According to various embodiments wherein the ion-exchange core includes a solid core material capable of ion-exchange, the solid core material can be macroporous silica, controlled pore glass (CPG), a macroporous polymer microsphere with internal pores, other porous materials as known to those of ordinary skill in the art of ion-exchange separation, or a combination thereof. The solid core material can have various surface features, including, for example, pores, cracks, crevices, pits, channels, holes, recesses, or grooves. The solid core material can include sodium oxide, silicon dioxide, sodium borate, or a combination thereof. The solid core material can be surface-activated to be capable of ion-exchange, for example, modification to be capable of cation-exchange or anion-exchange. Modification of the solid core material can include treatment of the solid core material to form cationic or anionic substituent groups on the surfaces of the solid core material. As used herein, the term “surface” can include external surfaces and/or internal surfaces. Internal surfaces can be, for example, the surfaces of voids or pores within the solid core material. The solid core material can be surface-activated to include one or more of quaternized functional groups, carboxylic acid groups, sulfonic acid groups, other cationic or anionic functional groups known to those of ordinary skill in the art of ion-exchange separation, or a combination thereof, on the surface of the solid core material.
According to various embodiments, the biopolymer polyelectrolyte can be a naturally-occurring biopolymer such as DNA. Examples of naturally-occurring DNA include sheared salmon sperm DNA, plasmid DNA, restriction digests of plasmid DNA, herring sperm DNA, calf thymus DNA, and other naturally derived DNA. An example of commercially purchased DNA is sheared salmon sperm DNA (Eppendorf AG, Hamburg, Germany). According to various embodiments, the naturally-occurring biopolymer DNA that can be used as a polyelectrolyte in the coating is distinguished as non-sample DNA to indicate that its source is not the sample that has been subjected to the biological reaction.
According to various embodiments, an ion-exchange core can be coated with a synthetic-polymer polyelectrolyte. According to various embodiments, the ion-exchange core can be coated with a water-soluble, or at least slightly water-soluble, polyanion. According to various embodiments, polyanion containing anionic functional groups can be used for coating. The anionic functional group can include carboxylic, boric, sulfonic, sulfinic, phosphoric, or phosphorus group, or a combination thereof. Polyanions containing inorganic acid functional groups can also be used. According to various embodiments, the water-soluble, or at least slightly water-soluble, polyanion can be prepared by copolymerization of an acid- or phenolic-containing monomer, for example, acrylic acid, methacrylic acid, 4-acetoxystyrene that can be hydrolyzed to give phenolic group, 4-styrenesulfonic acid, styrylacetic acid, or maleic anhydride, with a water soluble, at least slightly water-soluble or water-insoluble, co-monomer. According to various embodiments, the synthetic polymer can be can be a homopolymer, a copolymer, a terpolymer, or another polymer.
According to various embodiments, the synthetic polymer can include monomers including: (meth)acrylamide, N-methyl (methyl)acrylamide, N,N-dimethyl (methyl)acrylamide, N-ethyl (meth)acrylamide, N-n-propyl (meth)acrylamide, N-iso-propyl (meth)acrylamide, N-ethyl-N-methyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-(3-hydroxypropyl) (methy)acrylamide, N-vinylformamide, N-vinylacetamide, N-methyl-N-vinylacetamide, vinyl acetate that can be hydrolyzed to give vinylalcohol after polymerization, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, N-vinypyrrolidone, poly(ethylene oxide) (methy)acrylate, N-(meth)acryloxysuccinimide, positively charged comonomer can contribute from 0.01 percent to 100 percent, or 0.1 percent to 20.0 percent, or 1.0 percent to 10.0 percent.
According to various embodiments, other synthetic polymers can include homopolymers of styrene sulfonic acid, homopolymers and copolymers of acrylic acid, methacrylic acid, vinyl sulfonic acid, styrene sulfonic acid, 4-acetoxystyrene (precursor of 4-hydroxystyrene), and vinylphosphonic acid. According to various embodiments, other synthetic polymers can include homopolymers and copolymers of allyl amide hydrochloride, (3-acrylamidopropyl)trimethylammonium chloride, N-(3-aminopropyl)methacrylamide hydrochloride. The comonomers can include acrylamide, methacrylamide, vinyl acetate that can be converted into vinyl alcohol in a subsequent step, N,N-dimethylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-vinyl-N-methyl acetamide, 2-hydroxyethyl acrylate, and vinyl methyl ether.
According to various embodiments, the polyelectrolyte can include polyanions such as poly(styrenephosphoric acid), poly(phosphoric acid), homo-polymers and co-polymers of maleic acid, derivatives thereof and the like, homo-polymers and co-polymers of fumaric acid, derivatives thereof and the like, peptide-type synthetic polyanions such as poly(aspartic acid), poly(galactronic acid), poly(glutamic acid), nucleic acid type synthetic polyanions such as poly(adenylic acid), poly(inosinic acid), poly(uridylic acid), and natural polyanions such as polysaccharides.
According to various embodiments, the ion-exchange core can be coated with multiple layers of polyelectrolyte. The polyelectrolyte layers can include alternating layers of polyanions and polycations. Such alternating layers can provide strength durability and means to tailor the permeability of the coating. Provided the outer most polyelectrolyte of the multiple-layer structure is negatively charged, DNA fragments will not be immobilized from its solution. Small anions such as, for example, chloride and primers can penetrate or permeate through the multiple-layer structure to be coupled to the core.
According to various embodiments, the polyelectrolyte-coated particles can be provided as a mixture. The mixture can be incorporated in bed or column. According to various embodiments, the polyelectrolyte-coated particles can be provided in a bulk mode. A well-formed chromatographic bed of polyelectrolyte-coated particles is not necessarily required.
According to various embodiments, the polyelectrolyte-coated particles can be provided in a device. The device can be a microfluidic device having one or more pathway, wherein at least a portion of at least one pathway includes polyelectrolyte-coated particles. The device can have an inlet and an outlet in fluid communication with the polyelectrolyte-coated particles. The particles can be present in, for example, a column. As used herein, a column can be in a horizontal or vertical orientation, or in any position between a horizontal and a vertical orientation. The column can include a receptacle such as a cavity, chamber, reservoir, well, reaction region, bed, recess, or other receptacle suitable for containing or retaining polyelectrolyte-coated particles and the reaction products. The column can contain a plurality of polyelectrolyte-coated particles. The outlet of the device can be in fluid communication with a receptacle, such as a purified sample well, a tube, a glass plate, or another means of collecting a purified sample. According to various embodiments, the plurality of polyelectrolyte-coated particles can be a mixture.
According to various embodiments, a device for separating the reaction products can be provided. The device can include a mixture of polyelectrolyte-coated particles. The method can include adding the particles to the column of the device. The reaction products can be placed in or introduced to the inlet of the device. The reaction products can travel from the inlet through the column including polyelectrolyte-coated particles and optional additional material. The sample can be subjected to a combination of size-exclusion separation and ion-exchange resulting in a filtration and/or purification of the reaction products. The filtered and/or purified solution can be eluted or removed from the column through the outlet, and can be directed to a receptacle for analysis and/or further processing. The reaction products can be moved through the column by centripetal force. According to various embodiments, the plurality of polyelectrolyte-coated particles can be mixed with reaction products in bulk. The plurality of polyelectrolyte-coated particles form a first volume and the reaction products form a second volume where the first volume is less than or equal to the second volume.
According to various embodiments, separation of the reaction products using polyelectrolyte-coated particles can be achieved using a volume of polyelectrolyte-coated particles that is sufficient to provide adequate ion-exchange capacity, such as, ion-exchange of at least 80%, at least 90%, or at least 95% of the reaction products. The separation can occur in ten minutes or less, five minutes or less, or two minutes or less. The separation can include contacting the reaction products with the polyelectrolyte-coated particles for a period of time sufficient for the polyelectrolyte-coated particles to ion-exchange with the reaction products, and removing the purified reaction products from the polyelectrolyte-coated particles.
According to various embodiments, separating the purified reaction products from the particles can include removing the purified reaction products from the polyelectrolyte-coated particles, removing the particles from the purified reaction products, and/or sampling the purified reaction products from the mixture of particles and purified reaction products. An example of sampling the purified reaction products from the mixture of particles and purified reaction products can include analyzing the product in a tube by dipping a capillary directly into the tube and injecting into an instrument for further analysis.
According to various embodiments, separations for the polyelectrolyte-coated particles can include, for example, separation of polymerase chain reaction (PCR) products, separation of DNA sequencing reaction mixtures, and purification of RNA. Polyelectrolyte-coated particles can also be used for purification and/or separation of, for example, oligonucleotides, ligase chain reaction products, proteins, antibody binding reaction products, oligonucleotide ligation assay products, hybridization products, and antibodies. Polyelectrolyte-coated particles can also be used for desalting of biological products or reaction mixtures.
According to various embodiments, the selectivity of the polyelectrolyte-coated particles can depend on at least one of these criteria: (1) the molecular weight of the polyelectrolyte in the coating, (2) the chemical nature of the charged functionality and the charge density or molar percent of the charge of the polyelectrolyte in the coating, (3) the pore size of the ion-exchange core, (4) the nature of co-monomer in the coating polymer, and (5) the ratio of various co-monomers in the polymer. Each separation can provide different desirable features for at least one of the above criteria.
According to various embodiments, PCR products include materials that can interfere with downstream analysis. PCR products can include amplified target sequences (amplicons), buffer salts, surfactants, metal ions, enzymes (e.g. polymerase), nucleotides, oligonucleotide primers, and other components in solution. According to various embodiments, the target sequences of double-stranded DNA (dsDNA) can be analyzed, or used in subsequent enzymatic reactions that can be sensitive to at least some of the other PCR products. For example, free nucleotides and oligonucleotide primers can interfere with downstream enzymatic reactions. According to various embodiments, a polyelectrolyte-coated particle can separate nucleotides, oligonucleotide primers, and buffer salts from the target sequences of dsDNA. The resulting solution can contain purified PCR products in a desalted environment, and can be used in downstream reactions and analyses.
According to various embodiments, PCR purification can be directed toward separating larger double stranded DNA (dsDNA) from smaller ssDNA, and dsDNA (e.g. primer-dimer, an unwanted side reaction product which is a dsDNA, or other non-specifically amplified fragments), free nucleotides, and salts. According to various embodiments, PCR products for removal include nucleotides, primers with 45 nucleotides of ssDNA, primer-dimer with 60 bp of dsDNA, and dsDNA fragments smaller than 200 bp. According to various embodiments, primers, primer-dimer, and DNA fragments smaller than 100 bp can be captured by polyelectrolyte-coated particles. According to various embodiments, primers, primer-dimer, and DNA fragments smaller than 300 bp can be captured by polyelectrolyte-coated particles.
According to various embodiments, separation of larger dsDNA from other PCR products can include desalting. According to various embodiments, separation of larger dsDNA from other PCR products does not include desalting. There are circumstances when desalting can interfere with downstream processing such as separation and detection of the larger dsDNA PCR products.
According to various embodiments, the polyelectrolyte-coated particles can be subjected to the same PCR conditions as the PCR reactants prior to PCR termination and purification. The polyelectrolyte-coated particles can be subjected to temperature cycling from 65 to 95° C. The polyelectrolyte-coated particles can be bundled into a device that provides PCR and subsequent purification.
According to various embodiments, an ion-exchange core with a pore size in the range of 100 Angstroms to 2000 Angstroms, coated with a polyelectrolyte of Mw in the range of 1.0 megaDaltons to 3.0 megaDaltons provides PCR purification. According to various embodiments, an ion-exchange core with a pore size of 1000 Angstroms, coated with a polyelectrolyte of Mw of 1.7 megaDaltons to 2.6 megaDaltons provides PCR purification.
According to various embodiments, DNA sequencing reaction products can include material that can interfere with downstream analysis. The quality of separation for purification sequencing reaction products can be evaluated by analyzing at least one of these criteria: (1) residual dye artifacts (“blobs”) that appear as broad peaks superimposed over the sequence data, (2) peak intensity balance between large or small fragments, and (3) desalting of the sequencing reaction products.
According to various embodiments, DNA sequencing reaction products can include dye-labeled target sequences (the “sequencing ladder”), buffer salts, phosphate and pyrophosphate ions, metal ions, enzymes (e.g. polymerases), nucleotides, oligonucleotide primers, dye-labeled oligonucleotide primers, and other components such as residual, unincorporated dye-labeled-dideoxynucleotides (“dye terminators”). According to various embodiments, the dye-labeled target sequences can be subjected to electrophoretic analysis and DNA sequencing (“basecalling”) that can be sensitive to at least some of the other sequencing reaction products resulting in “blobs” that can cause errors in “basecalling.” According to various embodiments, capillary sequencers can use electrokinetic injection to introduce sequencing reaction products into the capillary for electrophoretic separation. The presence of salts in the sequencing reaction products can affect their introduction into the capillary, where a reduced salt concentration can enhance injection into the capillary.
According to various embodiments, polyelectrolyte-coated particles can remove material that produce “blobs” from and desalt sequencing reaction products. According to various embodiments, sequencing reaction products purified with polyelectrolyte-coated particles can have a salt concentration of less than or equal to 100 μM or less than or equal to 50 EM. A sample solution purified by polyelectrolyte-coated particles can be suitable for electrokinetic capillary injection. For these and other purposes, the polyelectrolyte-coated particle can have a size-exclusion limit of, for example, less than 10 nucleotides ssDNA, and can be able to remove small ions such as salts and dye-labeled primers from a sample solution while leaving ssDNA free in solution. Sequencing reaction purification using polyelectrolyte-coated particles can be used to separate ssDNA, for example, having a size of from 10 nucleotides to 1500 nucleotides or larger in size, from smaller components such as, for example, dye-labeled primers and salts.
According to various embodiments, separation of DNA sequencing reaction products can include separating primers, dye-labeled primers, and salts from dye-labeled ssDNA targets by substantially excluding dye-labeled ssDNA fragments having greater than 45 nucleotides.
According to various embodiments, purification of a sequencing reaction sample can remove dye-labeled dideoxynucleotides and salts from the sequencing reaction products by allowing such components to pass through the coating and react with the ion-exchange core, leaving a purified sample containing an amount of ssDNA relative to the pre-filtered amount, in an amount of 70% or more, 80% or more, 90% or more, or 95% or more.
According to various embodiments, an ion-exchange core with a pore size in the range of 5 Angstroms to 1000 Angstroms, coated with a polyelectrolyte of Mw in the range of 1000 Daltons to 6.0 megaDaltons provides sequencing reaction purification. According to various embodiments, an ion-exchange core with a pore size of 10 Angstroms to 50 Angstroms, coated with a polyelectrolyte of Mw of 2.4 megaDaltons to 4.9 megaDaltons provides sequencing reaction purification.
According to various embodiments, a method for purifying DNA sequencing reaction products can include providing a plurality of polyelectrolyte-coated particles, and contacting the DNA sequencing reaction products to separate dye-labeled ssDNA fragments. The method can include removing residual dye artifacts such as dye-labeled primers that can result in blobs in the sequencing analysis. The method can include maintaining dye-labeled ssDNA fragment lengths.
Coating Particles with Biopolymer:
The ion-exchange resin was converted to an ion-exchange by washing a 100 uL volume of resin with 100 uL of IM salt, acid, or base solution. The mixture was vortexed for 5 minutes, and spun down in a centrifuge. The supernatant was removed and another 1000 uL aliquot of salt, acid, or base solution was added. This was repeated three times. The ion-exchange core was then washed and spun five times using 1000 uL aliquots of DI water.
The ion-exchange cores were coated with DNA by repeated washings with 100 uL aliquots of 1 mg/mL sheared salmon sperm DNA (Eppendorf AG, Hamburg, Germany). Coating was performed by washing a 100 uL volume of resin with 100 uL of 1 mg/mL sheared salmon sperm DNA. The mixture was vortexed for 5 minutes, and spun down in a centrifuge. The supernatant was removed and another 100 uL aliquot of 1 mg/mL sheared salmon sperm DNA was added. This was repeated two times. The SEIE particles were then washed and spun three times using 1000 uL aliquots of DI water.
Coating Particles with Synthetic Polymer:
Poly(AA-co-DMA) polyelectrolyte for coating particles was provided by free radical polymerization of 0.32 g (4.44 mmol) of acrylic acid with 8.04 g (81.07 mmol) of N,N-dimethylacrylamide in 200 mL of DI water at 45° C. for 15 hours, using ammonium persulfate as an initiator and N,N,N′N′-tetramethylethylenediamine as a catalyst. The resulting polymer was purified by dialysis (50 K MWCO) and lyophilization to provide 7.70 g (92% yield) of the polymer; Mw=3.40 MDa, Mn=2.67 MDa.
Prior to coating, the anion-exchange resin was first converted into hydroxide anion-exchange core in the same manner as the previous example. A 1000 μL aliquot of DI water was added to 0.20-0.25 mL volume of an anion-exchange core in chloride form. The mixture was vortexed for 2 minutes, and spun down in a centrifuge. The supernatant was removed and this DI water washing was repeated two times. A 1000 μL aliquot of 2.0 M of ammonium hydroxide was added to the washed resin. The mixture was vortexed for 2 minutes, let standing for 5 minutes at ambient temperature, vortexed one minute, and spun down in a centrifuge. The supernatant was removed and this ammonium hydroxide washing was repeated two times. A 1000 μL aliquot of DI water was added to the pellet of ion exchange particles, vortexed for 1 minute, spun down by a centrifuge, and supernatant removed. This final DI water washing was repeated one more time. The resin was re-dispersed in 500 μL of DI water in a snap-capped polypropylene micro-centrifuge tube and stored in a refrigerator prior to use.
To a 1.5 mL microcentrifuge tube containing 15-20 μL of the wet anion exchange resin, 1.0 mL of the polymer solution (0.5 weight percent solution in deionized water) was added. It was vortexed for 1 minute, let standing at ambient temperature for 5 minutes, vortexed for additional one minute, spun down in a centrifuge, and supernatant removed. The polymer solution coating was repeated one more time. The pellet was then washed with 1 mL of DI water and spun down three times. The final washed resin was re-dispersed in 500 μL of DI water and stored in a refrigerator prior to use.
Alternatively, poly(AA-co-DMA) polyelectrolyte for coating particles was provided by polymerization under inert atmosphere (ultra pure nitrogen). To a 500-mL round bottom three-neck flask equipped with a 2” Teflon stirring blade, a glass bleeding tube for purging, and a water-cool condenser, was charged with 150.0 mL of Milli-Q water, 8.0160 g (80.86 mmol) of re-distilled N,N-dimethylacrylamide (Dajac), 0.3285 g (4.56 mmol) of redistilled acrylic acid (Aldrich Chemical) and 0.8043 g of an 1.9972 wt % aqueous solution of ammonium persulfate. This mixture was purged with ultra pure nitrogen at 150 mL/min for 60 minutes while stirred at a constant speed of 200 rpm. To purged solution, 80 μL of N,N,N′N′-tetramethylethylenediamine (Electrophoresis reagent from Aldrich Chemical) was added. The mixture was lowered into an oil bath at 50±1° C. and stirred at 200 rpm for a period of 3.5 hours. At the end of the reaction time, 50 mL of DI water was added and stirred for 5 minutes. The resulting water-clear solution was dialyzed with 50 K MWCO Spectra/Pro membrane in 5 Gal of DI water for 4 days, with water changed twice every 24 hours. The dialyzed solution was lyophilized to give 7.70 g (92.0% yield) of copolymer. Molecular weight was determined by GPC/MALLS to be 2.4 MDa Mw and 1.26 MDa Mn.
DNA Sequencing Reaction Purification by Polyelectrolyte-Coated Particles with Biopolymer:
For DNA sequencing reaction purification, a sample was prepared containing 400 uL dRhodamine Terminator Ready Reaction Mix (Applied Biosystems, Foster City, Calif., USA), 50 uL M13 universal reverse primer (3.2 pmol/uL), 25 uL template-amplicon (˜100 ng/uL), and 525 uL DI water. This solution was aliquoted into wells in a thermal cycler plate at a volume of 20 uL/well. The mixture was subjected to 25 cycles of heating, wherein each cycle included heating at 95° C. for 10 seconds, heating at 50° C. for 5 seconds, and heating at 60° C. for 120 seconds.
To provide the polyelectrolyte-coated particles with a biopolymer, 100 uL each of Aminex A-27, Bio-Rad AG 1-X8, and Bio-Rad AG 2-X8 were prepared as hydroxide polyelectrolyte-coated particles as described above. The resins were coated with 1 mg/mL sheared salmon sperm DNA as described above and washed with DI water. 100 uL of each of the coated anion exchange particles was mixed with 100 uL of Chromalite 30 SAG, prepared as hydrogen-form polyelectrolyte-coated particles, as described above, to form a mixed ion exchange bed. The mixed beds were washed with 1 mg/mL sheared salmon sperm DNA as described above and washed with DI water. 2 uL of the each of the coated mixed beds were added to a small MicroAmp® tube (Applied Biosystems, Foster City, Calif., USA). A mixed bed prepared from uncoated Aminex A-27 and Chromalite 30 SAG was prepared as a control.
To perform the purification, 1 uL of the above described sequencing reaction was added to each MicroAmp® tube containing 2 uL of the DNA-coated mixed bed ion exchange resins. The tubes were vortexed for 5 minutes after which 5 uL DI water was added to each tube and mixed with a pipette. The microcentrifuge tubes were spun at 5000×g and 5 μL of supernatant was removed from each tube and pipetted into a 96 well plate for analysis on a ABI Prism® 3100 sequencer. The samples were analyzed on the ABI Prism® 3100 using a 36 cm array, POP6® polymer (Applied Biosystems), and a standard sequencing module.
a-9d illustrate the results from this purification.
PCR Reaction Purification by Polyelectrolyte-Coated Particles with Biopolymer:
To demonstrate PCR reaction purification, a sample was prepared using a fluorescently-labeled primer so that the PCR product could be analyzed on a fluorescent capillary sequencer. A solution was prepared containing 102 uL PCR master mix (Applied Biosystems), 4 uL FAM-labeled forward primer (20 pmol/uL), 4 uL reverse primer (20 pmol/uL), 20 uL human gDNA, CEPH 1347-02 (50 ug/uL), and 70 uL deionized water (DI). This solution was aliquoted into wells in a thermal cycler plate at a volume of 20 uL/well. The mixtures were heated at 96° C. for 5 minutes, followed by 40 cycles of heating, wherein each cycle included heating at 96° C. for 30 seconds, then at 60° C. for 120 seconds.
Particles coated with a biopolymer, similar to the previous example were provided. To perform the purification, 1 uL of the above described solution was added to a MicroAmp tube containing 2 uL of the DNA-coated mixed bed ion exchange resins. The tube was vortexed for 5 minutes after which 5 uL DI water was added to the tube and mixed with a pipette. The microcentrifuge tube was spun at 5000×g and 5 μL of supernatant was removed, added to 5 uL deionized formamide, and pipetted into a 96 well plate for analysis on a ABI Prism® 3100 sequencer. The samples were analyzed on the ABI Prism® 3100 using a 36 cm array, POP-6® capillary electrophoresis polymer (Applied Biosystems), and a standard fragment analysis module.
a and 11b are a magnified view of a region of the electrophorograms illustrated in
DNA Sequencing Reaction Purification by Polyelectrolyte-Coated Particles with Synthetic Polymer:
For DNA sequencing reaction purification, a sample was prepared using a fluorescently-labeled primer so that the sequencing reaction product could be analyzed on a fluorescent capillary sequencer. A solution was prepared containing 400 uL dRhodamine Terminator Ready Reaction Mix (Applied Biosystems, Foster City, Calif., 50 uL M13 universal reverse primer (3.2 pmol/uL), 25 uL template-amplicon (˜100 ug/uL), and 525 uL DI water. This master solution was aliquoted into wells in a thermal cycler plate at a volume of 20 uL/well. The mixture was subjected to 25 cycles of heating, wherein each cycle included heating at 95° C. for 10 seconds, heating at 50° C. for 5 seconds, and heating at 60° C. for 120 seconds.
To provide the polyelectrolyte-coated particles coated with a synthetic polymer, 20 uL of Bio-Rad Macro-Prep High Q ion exchange resin was prepared as hydroxide polyelectrolyte-coated particles as described herein. The resin was coated with poly(acrylic acid-co-N,N-dimethylacrylamide), hereafter referred to as poly(AA-co-DMA), as described herein and washed with DI water. 20 uL of poly(AA-co-DMA)-coated Macro-Prep High Q was mixed with 20 uL of Chromalite 30 SAG (as hydrogen polyelectrolyte-coated particles, as described herein). 5 uL of the ion exchange particle mixture was added to a small MicroAmp® tube (Applied Biosystems, Foster City, Calif., USA).
To provide purification, 1 uL of the above described sequencing reaction was added to a MicroAmp tube containing 5 uL of the DNA-coated mixed bed ion exchange resins. The tube was vortexed for 5 minutes after which 5 uL DI water was added to the tube and mixed with a pipette. The microcentrifuge tube was spun at 5000×g and 5 μL of supernatant was removed and pipetted into a 96 well plate for analysis on a ABI Prism® 3100 sequencer. The samples were analyzed on the ABI 3100 using a 36 cm array, POP-6@ (Applied Biosystems), and a standard sequencing module.
Other dRhodamine sequencing reaction products were purified by polyelectrolyte-coated particles.
a and 15b illustrates the purification of sequencing reaction products purified by polyelectrolyte-coated particles including Powdex-PAO ion-exchange resin coated with poly(AA-co-DMA).
PCR Reaction Purification by Polyelectrolyte-Coated Particles with synthetic polymer:
PCR reaction product purification was provided by polyelectrolyte-coated particles with synthetic polymer. Macro-Prep HQ ion-exchange resin was coated with poly(AA-co-DMA).
For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities of ingredients, percentages or proportions of materials, reaction conditions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a range of “1 to 10” includes any and all subranges between (and including) the minimum value of 1 and the maximum value of 10, that is, any and all subranges having a minimum value of equal to or greater than 1 and a maximum value of equal to or less than 10, e.g., 5.5 to 10.
It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the,” include plural referents unless expressly and unequivocally limited to one referent. Thus, for example, reference to “a monomer” includes two or more monomers. Furthermore, the use of the term “including”, as well as other forms, such as “includes” and “included”, is not limiting.
It will be apparent to those skilled in the art that various modifications and variations can be made to various embodiments described herein without departing from the spirit or scope of the present teachings. Thus, it is intended that the various embodiments described herein cover other modifications and variations within the scope of the appended claims and their equivalents.
This application is a continuation-in-part of U.S. patent application Ser. No. 10/413,935, which claims priority from U.S. patent application Ser. No. 10/038,974, filed Jan. 4, 2002. Cross-reference is made to U.S. patent application Ser. Nos. 10/780,963, filed Feb. 18, 2003, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10413935 | Apr 2003 | US |
| Child | 11021039 | Dec 2004 | US |
| Parent | 10038974 | Jan 2002 | US |
| Child | 10413935 | Apr 2003 | US |
