Method for removing interfering components from a liquid sample prior to application to a chemical reagent test slide - Patents.com

Abstract

A method for using a chemical analyzer to remove components of a liquid sample that may interfere with tests performed on a test assay includes the steps of adding the liquid sample to a sample cup, transferring a quantity of the liquid sample to a mixing cup containing an IMAC (immobilized metal affinity chromatography) resin containing porous beads to form a sample / resin solution in the mixing cup, using a pipette of the chemical analyzer to repeatedly aspirate the sample / resin solution into a disposable pipette tip of the pipette and dispense the sample / resin solution from the pipette tip into the mixing cup to achieve a mixed sample / resin solution in the mixing cup, and allowing the mixed sample / resin solution in the mixing cup to settle so that interfering components of the liquid sample adhere to the porous beads and the beads settle to the bottom of the mixing cup, resulting in a purified liquid sample occupying an upper portion of the mixing cup that is free of interfering components, for subsequent application to the test assay.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application is related to U.S. Provisional Patent Application No. 62 / 986,988, entitled "Method For Removing Interfering Components Of A Liquid Sample Prior To Dispensing Same On A Chemical Reagent Test Slide", filed on March 9, 2020. The disclosure of this U.S. Provisional Patent Application is hereby incorporated by reference, and the priority based on this U.S. Provisional Patent Application is hereby claimed.

[0002] Furthermore, this application is related to U.S. Provisional Patent Application No. 62 / 987,077, entitled "Matrix And Associated Sample Or Mixing Cup Used For Removing Components Of A Liquid Sample", filed on March 9, 2020, with applicant IDEXX Laboratories, Inc. The disclosure of this U.S. Provisional Patent Application is hereby incorporated by reference herein.

[0003] (Technical Field) The present invention relates generally to techniques for applying a liquid sample onto a dry chemistry test slide, and more particularly to methods for removing impurities from a liquid sample. Even more specifically, the present invention relates to a method for purifying a liquid sample to remove components that can affect the accuracy of fluorescence or absorbance / reflection measurements performed by an automated chemical analyzer on the liquid sample.

Background Art

[0004] Certain assays used in dry chemistry and wet chemistry analysis techniques may be susceptible to the effects of interference components in liquid samples when fluorescence or absorbance / reflection measurements are made on the liquid samples. As an example, bile acid dry chemistry assay slides are highly susceptible to hemoglobin interference because the tetrazolium dye on the slide interacts primarily with hemoglobin. In this regard, reference should be made to FIG. 1 of the drawings, which is a graph of the actual reflectance density (vertical axis) versus the time (horizontal axis) of the bile acid assay (in seconds) for five undiluted blood samples with different hemoglobin concentrations (Hgb) (units are milligrams (mg) per deciliter (dL)). The graph of FIG. 1 shows the effect on the instrument progress curve from samples containing increasingly higher hemoglobin concentrations, and how such hemoglobin concentrations interfere with the measurement of bile acid reflectance density. Such interference is caused by hemolysis of the blood sample. The sample is placed on the assay slide at time = 0 in FIG. 1. The curves overlap at times <0 in FIG. 1, showing a baseline measurement of reflectance density of approximately 0.075 that represents a series of readings of the unused slide before the sample is applied. The curve labeled N in the graph of FIG. 1 represents the hypothetical bile acid reflectance density measurement in the absence of interference caused by hemolysis of the blood sample (i.e., Hgb = 0 mg / dL). Although perhaps not many, many commercially available bile acid assays are susceptible to the effects of hemoglobin interference.

[0005] One way contemplated to overcome this problem is to devise a bile acid assay composition that is not affected, or minimally affected, by the presence of hemoglobin in the liquid sample, regardless of whether dry chemistry or wet chemistry is used. As far as the inventors of the present invention are aware, such an assay is not currently available and is thought to require significant time and expense to develop. Another way to solve the problem of hemolysis interference in bile acid measurement, which is the means employed by the inventors of the present invention and described herein, is to lower the hemoglobin level in the sample prior to performing the test and use an existing currently available bile acid assay.

Summary of the Invention

[0006] An object of the present invention is to provide a method for removing interfering components of a liquid sample before applying the sample onto a dry chemistry reagent test slide.

[0007] Another object of the present invention is to provide a method for removing components of a liquid sample that may interfere with diagnostic measurements performed on the liquid sample.

[0008] Yet another object of the present invention is to provide a method for removing impurities from a liquid sample using functionalized particles prior to testing the sample.

[0009] A further object of the present invention is to provide a method for removing hemoglobin or other constituent substances of a liquid sample that may affect the accuracy of tests performed on the liquid sample.

[0010] Still another object of the present invention is to provide a liquid sample mixing / applying technique for removing components of the sample that may interfere with tests performed on the liquid sample and the measurement values derived therefrom.

[0011] Yet another object of the present invention is to provide a pretreated liquid sample in which the hemoglobin concentration is minimized or made negligible prior to application to a bile acid dry chemistry reagent test slide.

[0012] Yet a further object of the present invention is to adjust a liquid sample using an automated chemistry analyzer currently available for analyzing reagent test slides to reduce the concentration of interfering components that may affect the accuracy of fluorescence or absorbance / reflectance measurements derived from tests performed on the liquid sample.

[0013] Another object of the present invention is to provide a method for removing interfering components of a liquid sample using a conventional chemistry analyzer and applying the liquid sample to a conventional invariant dry chemistry reagent test slide.

[0014] Yet another object of the present invention is a method of pre-adjusting a liquid sample by removing or minimizing the presence of interfering components prior to application to a conventional reagent test slide, which advantageously avoids the time and expense of developing an assay for a test slide that is less susceptible to the effects of interfering components.

[0015] According to one aspect of the present invention, a liquid sample is prepared for testing by removing components that may interfere with the test performed on the sample. Such interfering components are advantageously removed by using a conventional currently available automated chemistry analyzer having a pipetting function. Further, advantageously, the pre-adjusted liquid sample with the interfering components removed can now be tested using an off-the-shelf assay such as a dry chemistry reagent test slide. This test slide used to make measurements on the liquid sample may still be susceptible to the effects of interfering components of the liquid sample, but since such components have been substantially removed from the sample, there is no need to modify the slide assay to be less susceptible to the effects of the components.

[0016] In a preferred form of the present invention, before applying the sample to the assay for inspection, by mixing the functionalized particles with the liquid sample in a mixing cup, the interfering components are removed from the liquid sample, or at least the concentration of the interfering components in the liquid sample is minimized. Such functionalized particles may, for example, be in the form of agarose-based porous beads to which the interfering components in the liquid sample adhere and are removed from the solution when the particles settle under the action of gravity (although the use of a gentle centrifugation to facilitate the sedimentation of the particles is also envisaged). The mixing of the functionalized particles and the liquid sample can be carried out using the dispensing / suction pipette of a conventional chemical analyzer.

[0017] When the functionalized particles and the liquid sample are completely mixed within the mixing cup, the mixture is allowed to stand for a first predetermined period in order to, for example, enable the particles to which the interfering components of the liquid sample adhere to settle to the bottom of the mixing cup under gravity. Next, the pipette of the chemical analyzer sucks a predetermined amount of the liquid sample from the upper part of the mixing cup to the pipette tip. The liquid sample at the upper part of the mixing cup should contain no interfering components or only have them at a low concentration.

[0018] As an optional step of the method for preventive purposes, the liquid sample aspirated into the pipette tip can be further allowed to stand for a second predetermined time so that the remaining functionalized particles (with or without interfering components adhering) aspirated into the pipette tip settle to the bottom of the pipette tip under gravity. After this predetermined second period has elapsed, the liquid containing the sedimented particles and / or interfering sample components occupying the bottom of the pipette tip is expelled or "dispensed" from the pipette tip back into the mixing cup. The liquid sample remaining in the pipette tip, which should substantially contain no interfering components of the liquid sample or only have them at a low concentration, or a portion thereof, can now be applied onto the chemical reagent test slide by the pipette of the chemical analyzer.

[0019] These and other objects, features, and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the invention to be considered in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0020]

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[0021] Here, reference should be made to FIGS. 2, 3, 4A, 4B, and 5-7 of the drawings. As described above, certain assays are subject to interference from tests performed on liquid samples and may be susceptible to components of the liquid sample that can affect the accuracy of the measurements obtained. For example, for a subject who is human or an animal and for whom liver dysfunction is suspected, a bile acid test is performed. In the case of an animal, a pre-meal blood sample is taken, and a post-meal blood sample is taken after a predetermined time has elapsed after the animal has finished eating. Both samples are brought to the laboratory, and the levels of bile acids are tested using a wet chemistry assay or a dry chemistry reagent test slide.

[0022] The problem in such bile acid assays is illustrated in the graph shown in FIG. 1 and, as already explained, is susceptible to hemoglobin (Hgb) which can interfere with the bile acid test performed on the patient's blood sample and render the measurements obtained inaccurate. Thus, the options in solving this problem can be an expensive and time-consuming route, either to develop a bile acid assay that does not react with hemoglobin in the blood sample, or to provide a method for substantially removing or at least minimizing the concentration of interfering components in the blood sample, in this case hemoglobin, before applying the sample to the assay for testing. This latter approach has been adopted by the inventors of the present invention and is further fully described herein. Of course, it should be understood that the method of the present invention described herein can be used to reduce the concentration of interfering components of liquid samples that can readily affect test assays and is not to be construed as limited to methods for removing hemoglobin from blood samples prior to their application to test assays. In fact, other components of liquid samples such as proteins can be removed or their concentration reduced using the method of the present invention.

[0023] As an example only, according to one form of the present invention used and tested in an automated chemical analyzer having a sample aspiration / delivery function that uses a pipette with a disposable tip, where the bile acid test slide susceptible to hemoglobin in the blood sample is used. Functionalized particles are pre-mixed in a mixing cup that holds the blood sample (as used herein, "blood sample" broadly refers to whole blood, diluted blood, plasma, serum, etc.). These functionalized particles attach the interfering component of the blood sample, in this example hemoglobin, to the particles, and the particles and the hemoglobin attached to the particles together precipitate to the bottom of the mixing cup by gravity.

[0024] Preferably, the functionalized particles assumed to be used to remove hemoglobin from the blood sample are agarose-based porous beads. Such particles are used for immobilized metal affinity chromatography (IMAC) applications functionalized by attaching ligands that will later coordinate to metal ions. To remove hemoglobin from the blood sample for bile acid testing, preferred particles are nitrilotriacetic acid (NTA), or iminodiacetic acid (IDA), with nickel ions (Ni 2+ ), or cobalt (Co 2+ ) or zinc (Zn 2+ ) ions-based chelating ligands. The porous beads in resin form are preferably purchased from Bio-Works Technologies AB in Uppsala, Sweden, under part number 40651 001 (for NTA with Ni -2 ). For further information on such porous beads and resins, reference should be made to Bio-Works Data Sheet DS 40650010, the disclosure of which is incorporated herein by reference.

[0025] More specifically, the types of resins manufactured by Bio-Works Technologies AB suitable for use in the method of the present invention are cross-linked agarose resins containing either of the two chelating groups NTA or IDA as described above incorporating one of four metal ions (nickel, cobalt, zinc, and optionally copper (Cu)). Preferably, the resin is packaged in water until use together with a preservative, or the resin may be packaged in ethanol. Resins of the following part numbers manufactured by Bio-Works Technologies AB, namely 40 651 001 (Ni-NTA), 40651 003 (Ni-NTA), 40651 010 (Ni-NTA), 40651 401 (Co-NTA), 40651 403 (Co-NTA), 40 651 410 (Co-NTA), 40 651 301 (Cu-NTA), 40651 303 (Cu-NTA), 40651 310 (Cu-NTA), 40 651 501 (Zn-NTA), 40651 503 (Zn-NTA), 40651 510 (Zn-NTA), 40650001 (Ni-IDA), 40650 003 (Ni-IDA), 40 650010 (Ni-IDA), 40650401 (Co-IDA), 40 650403 (Co-IDA), 40650410 (Co-IDA), 40650301 (Cu-IDA), 40 650 303 (Cu-IDA), 40 650 310 (Cu-IDA), 40650 501 (Zn-IDA), 40 650 503 (Zn-IDA), and 40650 510 (Zn-IDA) can be preferably used. It is also contemplated that within the scope of the present invention, bead resins forming the components of the buffer solution or diluent added to the liquid sample may be used.

[0026] Furthermore, a resin containing porous beads or non-porous beads may be used according to the method of the present invention. For example, a gel containing non-porous silica beads can be used. Suitable silica-based gels include, but are not limited to, gels generally known as "scavenger resins" manufactured by SiliCycle Inc., Quebec City, Quebec, Canada, and further called Imidazole-silica, AMPA silica, DOTA silica, DMT silica, and TAAcOH silica, and mesoporous thiol silica manufactured by Sigma-Aldrich, Inc. (now MilliporeSigma), owned by Merck KGaA, Darmstadt, Germany. Other materials that can be suitably used for removing interfering components in blood samples, especially hemoglobin, include NTA-Ni (and other metals such as Zn, Al, Mn, Co, etc.) resins, TALON (trademark) resins (EDTA) such as resins manufactured by Takara Bio USA, Inc., Mountain View, California, and the aforementioned IMAC resins including Iminodiacetate-Ni resins, and Fractogel (registered trademark)-Ni activation products manufactured by Merck KGaA, Darmstadt, Germany, and other materials such as TCEP immobilized resin products, ConA resin products, and protein depletion resins, each manufactured by Thermo Fisher Scientific Inc., Waltham, Massachusetts.

[0027] Immobilized metal affinity chromatography (abbreviated as IMAC) is a common technique used for the purification of recombinant proteins tagged with histidine or polyhistidine. An IMAC resin containing agarose-based porous beads is added to a disposable (discardable) mixing cup as a way to reduce sample processing related to hemolysis interference in bile acid assays, that is, to remove or reduce the amount of hemoglobin in a blood sample before pipetting the sample onto a bile acid test slide, because hemoglobin in the sample binds to the immobilized metal ions in the IMAC resin.

[0028] Figure 2 shows the effectiveness of the method of the present invention, which will be described in more detail below. As can be seen in the graph shown in Figure 2, the absorption spectrum of the hemoglobin content of a canine plasma sample without IMAC treatment is overlaid on the absorption spectrum of the same sample treated with IMAC according to the method of the present invention. It is clear from the graph that using this treatment protocol, the hemoglobin content in the sample was reduced to one-fifth, i.e., the hemoglobin (Hgb) in this exemplary sample decreased from about 500 mg / dL to about 100 mg / dL after subjecting the blood sample to IMAC treatment according to the method of the present invention.

[0029] A preferred series of steps according to the present invention, which is preferably carried out by an automated chemical analyzer 2 having a pipette 4 for aspiration / delivery with a disposable tip 6 attached, processes a liquid sample 8 to remove interfering components of the liquid sample 8 or at least reduce their content, as shown in Figure 3 of the drawings. Further, reference should also be made to U.S. Patent No. 9,116,129, entitled "Chemical Analyzer," issued to Rich et al. on August 25, 2015, U.S. Patent No. 9,797,916, entitled "Chemical Analyzer," issued to Connolly et al. on October 24, 2017, and U.S. Patent No. 9,823,109, entitled "Chemical Analyzer," issued to Garrepy et al. on November 21, 2017, which disclose chemical analyzers capable of performing the steps of the method of the present invention. The disclosures of each of the foregoing patents are incorporated herein by reference. Each of the foregoing patents has a recorded assignment to IDEXX Laboratories, Inc., of Westbrook, Maine. Chemical analyzers that are currently available and capable of practicing the method of the present invention are sold by IDEXX Laboratories, Inc. and are known in the industry by their names, Catalyst One (trademark) and Catalyst Dx (trademark).

[0030] According to the sample processing and interference component removal method of the present invention, for example, a sample cup 10 containing a liquid sample 8 such as whole blood or diluted blood, serum, or plasma is loaded into a chemical analyzer 2. Alternatively, a whole blood sample can be loaded into a centrifuge cup 12 of a whole blood separator 14 of the chemical analyzer 2, and after centrifugation, plasma or other separated components can be transferred to a mixing cup 16 of consumables associated with the chemical analyzer 2 (for the description of the blood separator 14, centrifuge cup 12, and mixing cup 16, refer to the aforementioned U.S. Patent Nos. 9,116,129, 9,797,916, and 9,823,109). In this example, one or more reagent test slides 18, which are bile acid test slides, are also loaded into the chemical analyzer 2. The IMAC resin containing porous beads is placed in a reagent cup of consumables that can be used as the aforementioned mixing cup 16.

[0031] More specifically, in a preferred form, the IMAC resin is lyophilized in a solution of about 7 percent (7%) dextran / sucrose, more specifically about 3.5 percent (3.5%) dextran and about 3.5 percent (3.5%) sucrose, to form a physically stable cake 20. The dextran / sucrose solution keeps the lyophilized resin cake 20 at the bottom of the mixing cup 16.

[0032] Next, a liquid sample 8, such as blood, serum, or plasma, is transferred to a mixing cup 16 by a pipette 4 of a chemical analyzer 2 by aspirating a certain amount of the liquid sample 8 from a sample cup 10 to the pipette tip 6 and discharging that amount or a portion thereof from the pipette tip 6 into the mixing cup 16 containing the dry resin cake 20. If it is desired to use a diluted blood sample, the sample 8 is preferably mixed with a diluent that acts on the resin to optimize the resin for binding to interfering components (e.g., hemoglobin in the case of a bile acid assay), and the dilution step occurs before or when the blood sample 8 is added to the mixing cup 16 containing the IMAC resin. For example, the pipette tip 6 first aspirates a first predetermined amount of diluent buffer, then aspirates a second predetermined amount of the blood sample 8 from the sample cup 10, and places the sample / buffer mixture into the mixing cup 16 where the resin cake 20 is located. Alternatively, so that the diluent buffer in the pipette tip 6 does not touch the liquid sample 8 in the sample cup 10, a certain amount of the liquid sample 8 can first be aspirated and placed into the mixing cup 16, and then the diluent buffer can be aspirated and placed into the mixing cup 16.

[0033] The liquid sample 8 added to the resin cake 20 present in the mixing cup 16 dissolves the cake 20 into a resuspension of the IMAC resin containing the porous beads in the mixing cup 16.

[0034] Next, using the pipette 4 of the chemical analyzer 2, the combined sample / resin solution is aspirated to the pipette tip 6 and the solution is discharged from the pipette tip 6 back into the mixing cup 16, thereby mixing the liquid sample 8 and the IMAC resin beads, and the aspiration step and the subsequent discharge step are repeated several times to ensure complete mixing of the resuspended resin and the sample 8.

[0035] Here, the sample / resin solution in the mixing cup 16 can be allowed to stand (i.e., incubated) for a predetermined time, for example, for about 5 minutes or less to about 10 minutes or more. This time is mainly determined by the time required for the particles to settle from the liquid portion for aspiration after cleaning or substantially cleaning by the pipette 4. Since higher density particles settle faster than lower density particles, the predetermined time for the particles to settle in the mixing cup 16 can vary from about 1 minute to about 15 minutes. The interaction between the particles and hemoglobin appears to occur relatively rapidly, and thus an incubation (settling) time of about 2 minutes or less to about 3 minutes may be sufficient. During this incubation time, hemoglobin or other interfering components in the liquid sample adhere to the porous beads of the IMAC resin, and the beads with hemoglobin attached and the beads without attachment settle to the bottom 22 below the mixing cup 16 as shown in FIGS. 4A and 4B of the drawings, and the liquid sample that does not contain hemoglobin or contains only a minimal amount occupies the upper part 24 of the mixing cup 16.

[0036] Some of the mixing cups 16 used in the automated analyzer and instrument 2 have distinct geometric shapes, and such geometric shapes should be considered when the liquid sample 8 that does not contain interfering components and occupies the upper part 24 of the mixing cup 16 is aspirated by the pipette 4 to the tip 6 for applying the sample 8 onto the test assay 18. For example, FIGS. 4A and 4B of the drawings show in cross-section a particular preferred frustoconical shape of the mixing cup 16 used with the IDEXX Laboratories instruments of the aforementioned Catalyst One (trademark) and Catalyst Dx (trademark).

[0037] In FIG. 4A, the mixing cup 16 is shown as containing a 100 microliter (ul) sample and 33 microliters (ul) of resin that has been dried and rehydrated by the sample. In FIG. 4B, the same mixing cup 16 is shown as having the same example and sample amount as in FIG. 4A, but less resin, namely, a 100 microliter (ul) sample and 25 microliters (ul) of resin that has been dried and rehydrated by the sample. In each example of the mixing cup 16 shown in FIGS. 4A and 4B, the particles were lyophilized before adding the 100 microliter (ul) sample so that the total volume of the sample / bead mixture would be equal to about 100 microliters (ul) in each example. In other words, once the liquid sample 8 is added to the mixing cup 16, the resin rehydrates from the sample 8 and reaches approximately its original hydrated volume. Thus, after a predetermined incubation time has elapsed to allow sedimentation of the beads and hemoglobin or other interfering components to the lower portion 22 of the mixing cup 16 as shown in FIGS. 4A and 4B, the controller of the analyzer 2 should be programmed to lower the pipette tip 6 into the mixing cup 16 to a depth (i.e., the vertical height above the bottom inside the cup) necessary to aspirate only the liquid sample 8 occupying the upper portion 24 of the mixing cup 16, identified as the "upper space" in FIGS. 4A and 4B, so as not to draw the sedimented bead / hemoglobin mixture 26 located in the lower portion 22 of the mixing cup 16 into the pipette tip 6.

[0038] For example, in the specific geometric shape of the mixing cup 16 shown in FIGS. 4A and 4B used in instruments such as IDEXX Laboratories' Catalyst One™ and Catalyst Dx™, for a 100 microliter (μl) mixture of sample and 33 pL of rehydrated beads, after the incubation time has elapsed, the automated instrument 2 should be programmed to aspirate some or all of the sample 8 that occupies a 2.50 millimeter (mm) vertical "upper space" A (see FIG. 4A) located above the settled beads and hemoglobin solution 26 of 3.40 millimeters (mm) B with pipette 4, while for a 100 microliter (μl) mixture of sample and 25 pL of rehydrated beads, after the incubation time has elapsed, the automated instrument 2 should be programmed to aspirate some or all of the sample 8 that occupies a 3.20 millimeter (mm) vertical "upper space" C (see FIG. 4B) located above the settled beads and hemoglobin solution 26 of 2.70 millimeters (mm) D with pipette 4. In other words, the mixing cup 16 shown in FIG. 4A contains approximately 67 microliters (μl) of liquid available for (testing) and approximately 33 microliters (μl) of rehydrated resin particles with respect to a total volume of approximately 100 microliters (μl), and the mixing cup 16 shown in FIG. 4B contains approximately 75 microliters (μl) of liquid available for (testing) and approximately 25 microliters (μl) of rehydrated resin particles with respect to a total volume of approximately 100 microliters (μl).

[0039] After allowing the solution in the mixing cup 16 to settle to remove hemoglobin or other interfering components for other purposes and remaining unattached beads, the pipette 4 of the analyzer 2 preferably avoids or minimizes the aspiration of settled beads and hemoglobin that may interfere with the measurements obtained in the test assay 18 by aspirating only the desired amount of liquid sample 8 from the upper portion 24 (i.e., the "upper space") of the mixing cup 16 to a new (clean) tip 6 attached to the pipette.

[0040] As an optional step of the method of the present invention for preventive purposes, the liquid sample solution 8 aspirated into the pipette tip 6 is allowed to stand for a second predetermined incubation time, i.e., about 1 minute to about 15 minutes, or about 5 minutes or less to about 10 minutes or more, or about 2 minutes or less to about 3 minutes (in particular, to sediment the particles to which hemoglobin has adhered). Thus, when beads (whether or not the residual interfering components of the liquid sample 8 aspirated into the pipette tip are attached) are present in the aspirated sample solution 8, they can be sedimented to the discharge end of the pipette tip 6. After the time for allowing the beads to sediment at the pipette tip 6 has elapsed, the controller of the analyzer 2 expels a small amount of the solution at the pipette tip 6 containing sedimented components that may contain beads or beads to which hemoglobin is attached, such as, for example, about 10 microliters (μl) to about 50 microliters (μl), from the pipette tip 6 and "returns" it to the mixing cup 16 in order to ensure that almost all of the beads and / or remaining hemoglobin are removed from the solution remaining at the pipette tip 6 that is finally applied to the bile acid test slide 18. Such a series of steps is shown in FIG. 5 of the drawings. The bile acid test assay 18 in which the sample solution is metered and placed is still susceptible to the influence of hemoglobin, but finally there is little or no hemoglobin remaining in the solution applied to the test assay 18 that interferes with the bile acid test performed by the chemical analyzer 2 and the measurements obtained.

[0041] The mixing cup 16 of the consumable pre-loaded with the beads / resin cake 20 is preferably used in the implementation of the method of the present invention for removing interfering components from the liquid sample 8, as described herein and shown in the drawings. However, by pre-loading the centrifuge cup 12 of the blood separator of the chemical analyzer with resin in either dry or liquid form, or by adding the resin to the centrifuge cup 12 after centrifugation, hemoglobin is sedimented from the liquid sample 8 towards the bottom 28 of the centrifuge cup 12, and an amount of the sample occupying the upper part 30 of the centrifuge cup 12 is aspirated by the pipette 4 to the pipette tip 6 for application to the test assay 18. It should be noted that this is also considered to be within the scope of the present invention. As described above, the sample aspirated by the pipette 4 can be sedimented at the pipette tip 6 so that any remaining beads can be expelled from the pipette tip 6 before dispensing the sample onto the test assay 18 as shown in FIG. 5. Further, although the resin containing the beads is described herein as being present in the mixing cup 16 as a physically stable cake 20, it is also envisioned that the resin is in liquid form within the sealed mixing cup 16 and the seal is broken by downward movement of the pipette tip 6, or that the resin is present in another sealed cup and transferred to the mixing cup 16 by the pipette 4.

[0042] Here, a method for removing interfering components from a liquid sample 8 such as a blood sample (e.g., diluted, undiluted, whole blood, serum, plasma, etc.) will be further described.

[0043] More specifically, according to one embodiment of the present invention, a method of using a chemical analyzer 2 to remove components of a liquid sample 8 that may interfere with the tests performed in the test assay 18 is disclosed herein. The chemical analyzer 2 is associated with a sample cup 10, a mixing cup 16, and a disposable pipette tip 6, and is capable of aspirating the liquid sample 8 into the pipette tip 6 and discharging the liquid sample 8 from the pipette tip 6, and is associated with a vertically movable pipette 4 capable of applying the liquid sample 8 to the test assay 18.This method includes the steps of adding a liquid sample 8 containing interfering components to a sample cup 10; transferring the liquid sample 8 containing interfering components from the sample cup 10 to a mixing cup 16 containing an IMAC (immobilized metal affinity chromatography) resin containing porous beads, and forming a sample / resin solution in the mixing cup 16 with the liquid sample 8 and the IMAC resin; completely mixing the sample / resin solution in the mixing cup 16, and using a pipette 4 of a chemical analyzer 2 to mix the sample / resin solution in the mixing cup 16 by repeatedly aspirating the sample / resin solution into the pipette tip 6 and then discharging the sample / resin solution from the pipette tip 6 back into the mixing cup 16 as needed to achieve a mixed sample / resin solution; allowing the mixed sample / resin solution in the mixing cup 16 to stand for a predetermined time selected such that at least a portion of the interfering components of the liquid sample 8 can adhere to the porous beads of the IMAC resin, and at least a portion of the porous beads with the interfering components attached or the porous beads without the interfering components attached can settle in the mixing cup and occupy the bottom 22 of the mixing cup, and as a result of the settlement of the porous beads with the interfering components attached, a purified liquid sample is formed that occupies the upper portion 24 of the mixing cup 16 and does not contain interfering components or has them only at a lower concentration than the liquid sample; and aspirating a predetermined amount of the purified liquid sample occupying the upper portion 24 of the mixing cup 16 from the mixing cup 16 into the pipette tip 6 in order to later apply a selected amount of the purified liquid sample that does not contain interfering components or has them only at a low concentration to an assay 18.

[0044] The above-mentioned predetermined time is preferably about 5 minutes to about 10 minutes. Further, the IMAC resin preferably contains agarose-based porous beads.

[0045] Even more preferably, the IMAC resin is lyophilized in a solution of about 2 percent (2%) to about 14 percent (14%) dextran / sucrose, or more preferably about 7 percent (7%) dextran / sucrose. More specifically, the IMAC resin is lyophilized in a solution of about 2 percent (2%) to about 10 percent (10%) dextran and about 2 percent (2%) to about 10 percent (10%) sucrose, or more preferably about 3.5 percent (3.5%) dextran and about 3.5 percent (3.5%) sucrose.

[0046] In one form, the IMAC resin is formed as a physically stable cake 20 and is located at the bottom 22 of the mixing cup 16.

[0047] The method of the present invention can be used to remove interfering components from a number of different types of liquid samples 8 to be analyzed. In one particular application, when a bile acid assay is being examined by the chemical analyzer 2, the interfering component removed from the liquid sample 8 is hemoglobin.

[0048] In yet another aspect of the present invention, a method is disclosed herein for using a chemical analyzer 2 to remove components of a liquid sample 8 that may interfere with the tests performed on test assay 18. The chemical analyzer 2 is associated with a sample cup 10, a mixing cup 16, and a disposable pipette tip 6 having a discharge end. The pipette tip 6 is capable of aspirating the liquid sample 8 and discharging the liquid sample 8 therefrom, and is associated with a vertically movable pipette 4 capable of applying the liquid sample 8 to the test assay 18. The method includes adding a liquid sample 8 containing interfering components to the sample cup 10, transferring the liquid sample 8 containing interfering components from the sample cup 10 to a mixing cup 16 containing an IMAC (immobilized metal affinity chromatography) resin containing porous beads, and forming a sample / resin solution in the mixing cup 16 with the liquid sample 8 and the IMAC resin. Mixing the sample / resin solution in the mixing cup 16 completely to achieve a mixed sample / resin solution by aspirating the sample / resin solution into the pipette tip 6 and then discharging the sample / resin solution from the pipette tip 6 back into the mixing cup 16 as needed using the pipette 4 of the chemical analyzer 2. Allowing the mixed sample / resin solution in the mixing cup 16 to stand for a first predetermined time selected such that at least a portion of the interfering components of the liquid sample 8 can adhere to the porous beads of the IMAC resin, and at least a portion of the porous beads with the interfering components attached or the porous beads without the interfering components attached settle within the mixing cup 16 to occupy the bottom 22 of the mixing cup, resulting in the formation of a first stage purified liquid sample that does not contain the interfering components or has them only at a first concentration lower than that of the liquid sample 8 and occupies the upper portion 24 of the mixing cup 16.

[0049] This method includes the steps of aspirating a predetermined amount of the first-stage purified liquid sample occupying the upper portion 24 of the mixing cup 16 from the mixing cup 16 to the pipette tip 6, and the first-stage purified liquid sample aspirated into the pipette tip 6 is such that the remaining interfering components of the liquid sample in the first-stage purified liquid sample of the pipette tip 6 can adhere to the porous beads of the IMAC resin remaining in the first-stage purified liquid sample of the pipette tip 6, and at least a part of the remaining porous beads with the interfering components attached or the remaining porous beads without the interfering components attached settle within the pipette tip 6 to form a sedimentation solution 32 occupying the bottom 34 of the pipette tip 6 near the discharge end of the pipette tip 6. As a result of the sedimentation of the porous beads with the interfering components attached and the non-attached porous beads, the sedimentation solution 32 and a second-stage further purified liquid sample occupying the upper portion 36 of the pipette tip 6, which does not contain the interfering components or has only a second lower concentration than the first-stage purified liquid sample, are formed. A step of allowing to stand for a second predetermined time selected such that; and a step of discharging the sedimentation solution 32 occupying the bottom 34 of the pipette tip 6 from the pipette tip 6 to the mixing cup 16 while leaving the second-stage further purified liquid sample in the pipette tip 6 for applying a selected amount of the second-stage further purified liquid sample, which does not contain the interfering components or has only a second lower concentration, to the later inspection assay 18.

[0050] In the above method, the first predetermined time is preferably about 5 minutes to about 10 minutes, the second predetermined time is preferably about 5 minutes to about 10 minutes, the IMAC resin can include agarose-based porous beads, the IMAC resin is preferably lyophilized in a solution of about 7 percent (7%) dextran / sucrose, and even more preferably, the IMAC resin is lyophilized in a solution of about 3.5 percent (3.5%) dextran and about 3.5 percent (3.5%) sucrose. The IMAC resin is formed as a physically stable cake 20 and is located at the bottom 22 of the mixing cup 16. This method is used to remove hemoglobin as an interfering component that may affect the test performed in the bile acid test assay 18.

[0051] According to yet another form of the method of the present invention for removing components of the liquid sample 8 that may interfere with the test performed in the test assay 18, again the chemical analyzer 2 is used. The chemical analyzer 2 includes a blood separator 14 and a centrifuge cup 12, a mixing cup 16, and a disposable pipette tip 6 is attached, and it is possible to suck liquid into the pipette tip 6 and discharge liquid from the pipette tip 6, and it has a vertically movable pipette 4 capable of applying liquid to the test assay 18.This method includes the steps of adding a blood sample 8 containing interfering components to a centrifuge cup 12; centrifuging the blood sample in the centrifuge cup 12 using a blood separator 14 of a chemical analyzer 2 to yield a separated blood component containing interfering components in the centrifuge cup 12; transferring the separated blood component containing interfering components from the centrifuge cup 12 to a mixing cup 16 containing an IMAC (immobilized metal affinity chromatography) resin containing porous beads to form a blood component / resin solution in the mixing cup 16 with the separated blood component and the IMAC resin; completely mixing the blood component / resin solution in the mixing cup 16 by repeating, as necessary, the suction of the blood component / resin solution into a pipette tip 6 and subsequent ejection of the blood component / resin solution from the pipette tip 6 back into the mixing cup 16 to mix the blood component / resin solution in the mixing cup 16 using a pipette 4 of the chemical analyzer 2 to achieve a mixed blood component / resin solution; allowing the mixed blood component / resin solution in the mixing cup 16 to stand for a predetermined time selected such that at least a portion of the interfering components of the blood component can adhere to the porous beads of the IMAC resin, and at least a portion of the porous beads with interfering components attached or porous beads without interfering components attached can settle in the mixing cup 16 to occupy the bottom 22 of the mixing cup, and as a result of the settling of the porous beads with interfering components attached, a purified blood component is formed that occupies the upper portion 24 of the mixing cup 16 and does not contain interfering components or has them only at a lower concentration than the blood component; and suctioning a predetermined amount of the purified blood component occupying the upper portion of the mixing cup 16 from the mixing cup 16 into the pipette tip 6 for later application of a selected amount of the purified blood component, which does not contain interfering components or has them only at a low concentration, to an assay 18.

[0052] According to the above method, the predetermined time is preferably about 5 minutes to about 10 minutes, the IMAC resin can include agarose-based porous beads, the IMAC resin is preferably lyophilized in a solution of about 7 percent (7%) dextran / sucrose, and even more preferably, the IMAC resin is lyophilized in a solution of about 3.5 percent (3.5%) dextran and about 3.5 percent (3.5%) sucrose. The IMAC resin is formed as a physically stable cake 20 and is located at the bottom 22 of the mixing cup 16. This method is used to remove hemoglobin as an interfering component that may affect the test performed in the bile acid test assay 18.

[0053] According to yet another form of the method of the present invention for removing components of the blood sample 8 that may interfere with the tests performed on the test assay 18, a chemical analyzer 2 is used which has a blood separator 14 and a centrifuge cup 12, a mixing cup 16, and a disposable pipette tip 6 having a discharge end, to which suction of liquid and discharge of liquid from the pipette tip 6 are possible, and a vertically movable pipette 4 to which application of liquid to the test assay 18 is possible. This method includes the steps of adding a blood sample 8 containing interfering components to the centrifuge cup 12; centrifuging the blood sample 8 in the centrifuge cup 12 using the blood separator 14 of the chemical analyzer 2 to yield separated blood components containing interfering components in the centrifuge cup 12; transferring the separated blood components containing interfering components from the centrifuge cup 12 to a mixing cup 16 containing an IMAC (immobilized metal affinity chromatography) resin containing porous beads, to form a blood component / resin solution in the mixing cup 16 with the separated blood components and the IMAC resin; mixing the blood component / resin solution in the mixing cup 16 completely by repeating, if necessary, suction of the blood component / resin solution into the pipette tip 6 and subsequent discharge of the blood component / resin solution from the pipette tip 6 back into the mixing cup 16 using the pipette 4 of the chemical analyzer 2 to achieve a mixed blood component / resin solution; allowing the mixed blood component / resin solution in the mixing cup 16 to stand for a first predetermined time selected such that at least a portion of the interfering components of the blood components can adhere to the porous beads of the IMAC resin, and at least a portion of the porous beads with interfering components attached or porous beads without interfering components attached can settle in the mixing cup 16 to occupy the bottom 22 of the mixing cup, and as a result of the settling of the porous beads with interfering components attached, a first stage of purified blood components is formed that occupy the upper portion 24 of the mixing cup 16 that does not contain interfering components or has them only at a first concentration lower than the blood components.

[0054] This method includes the steps of aspirating a predetermined amount of the first-stage purified blood components occupying the upper part 24 of the mixing cup 16 from the mixing cup 16 to the pipette tip 6, and the first-stage purified blood components aspirated into the pipette tip 6, where the remaining interfering components of the blood components in the first-stage purified blood components of the pipette tip 6 can adhere to the porous beads of the IMAC resin remaining in the first-stage purified blood components of the pipette tip 6, and at least a part of the remaining porous beads with the interfering components attached or the remaining porous beads without the interfering components attached settle within the pipette tip 6 to form a sedimentation solution 32 occupying the bottom 34 of the pipette tip 6 near the discharge end of the pipette tip 6. As a result of the sedimentation of the porous beads with the interfering components attached and the non-attached porous beads, a second-stage further purified blood component occupying the upper part 36 of the pipette tip 6 that does not contain the interfering components or has only a second lower concentration than the first-stage purified blood components is formed. A step of allowing to stand for a second predetermined time selected to be such that, and a step of discharging the sedimentation solution 32 occupying the bottom 34 of the pipette tip 6 from the pipette tip 6 to the mixing cup 16 while leaving the second-stage further purified blood component in the pipette tip 6 for applying a selected amount of the second-stage further purified blood component that does not contain the interfering components or has only the second lower concentration to the later inspection assay 18.

[0055] According to the above method, the first predetermined time is preferably about 5 minutes to about 10 minutes, the second predetermined time is preferably about 5 minutes to about 10 minutes, the IMAC resin can include agarose-based porous beads, the IMAC resin is preferably freeze-dried in a solution of about 7 percent (7%) dextran / sucrose, and even more preferably, the IMAC resin is freeze-dried in a solution of about 3.5 percent (3.5%) dextran and about 3.5 percent (3.5%) sucrose. The IMAC resin is formed as a physically stable cake 20 and is located at the bottom 22 of the mixing cup 16. This method is used to remove hemoglobin as an interfering component that may affect the tests performed in the bile acid test assay 18.

[0056] Furthermore, the present invention relates to an IMAC (immobilized metal affinity chromatography) resin that contains porous beads and is used in a chemical analyzer 2 to remove components of a liquid sample 8 that may interfere with the tests performed on a test assay 18 by the chemical analyzer 2. The IMAC resin is freeze-dried in a solution of about 3.5 percent (3.5%) dextran and about 3.5 percent (3.5%) sucrose to form a physically stable cake 20.

[0057] Furthermore, the present invention relates to a mixing cup 16, such as the mixing cup 16 shown in FIG. 6, which has an internal space 38 and is used to mix a liquid sample 8 in a chemical analyzer 2. The mixing cup 16 contains porous beads and includes an IMAC (immobilized metal affinity chromatography) resin that is used by the chemical analyzer 2 to remove components of a liquid sample 8 that may interfere with the tests performed on a test assay 18 by the chemical analyzer 2. This IMAC resin is located within the internal space 38 of the mixing cup 16.

[0058] Even more preferably, the mixing cup 16 used to mix the liquid sample 8 in the chemical analyzer 2 includes a bottom 22, an upper portion 24 located above the bottom 22, and an IMAC (immobilized metal affinity chromatography) resin containing porous beads and used by the chemical analyzer 2 to remove components of the liquid sample 8 that may interfere with the tests performed on the test assay 18 by the chemical analyzer 2. The IMAC resin is lyophilized in a solution of about 3.5 percent (3.5%) dextran and about 3.5 percent (3.5%) sucrose to form a physically stable cake 20, and this resin cake 20 is located at the bottom 22 of the mixing cup 16. The resin cake 20 re-suspends in liquid form when the liquid sample 8 is added to the mixing cup 16 to form a sample / resin solution in the mixing cup. When the sample / resin solution in the mixing cup 16 is mixed, a mixed sample / resin solution is achieved. When the mixed sample / resin solution in the mixing cup 16 is allowed to stand for a predetermined time, at least a portion of the interfering components of the liquid sample 8 adhere to the porous beads of the IMAC resin, and at least a portion of the porous beads with the interfering components attached or the porous beads without the interfering components attached settle in the mixing cup 16 and occupy the bottom 22 of the mixing cup 16. As a result of the settling of the porous beads with the interfering components attached, a purified liquid sample is formed that occupies the upper portion 24 of the mixing cup 16 and does not contain the interfering components or has them only at a lower concentration than the liquid sample 8. The purified liquid sample that occupies the upper portion 24 of the mixing cup 16 is provided for later application of a selected amount of the purified liquid sample that does not contain the interfering components or has them only at a low concentration to the test assay 18.

[0059] More specifically, the mixing cup 16 used to mix the liquid sample 8 in the chemical analyzer 2 includes an internal space 38, contains beads, and further includes a resin used by the chemical analyzer 2 to remove components of the liquid sample 8 that may interfere with the tests performed on the test assay 18 by the chemical analyzer 2. The resin is located within the internal space 38 of the mixing cup 16. Preferably, the resin is an IMAC (immobilized metal affinity chromatography) resin.

[0060] In one form, the mixing cup 16 includes an inner side wall 21 and a bottom wall 23, and the resin is lyophilized. The lyophilized resin covers at least one of at least a portion of the inner side wall 21 of the mixing cup 16 and at least a portion of the bottom wall 23 of the mixing cup 16.

[0061] In yet another form, the mixing cup 16 further includes a bottom 22 and an upper portion 24 located above the bottom 22. The lyophilized resin re-suspends in liquid form when the liquid sample 8 is added to the mixing cup 16 to form a sample / resin solution within the mixing cup 16. When the sample / resin solution within the mixing cup 16 is mixed, a mixed sample / resin solution is achieved. When the mixed sample / resin solution within the mixing cup 16 is allowed to stand for a predetermined time, at least a portion of the interfering components of the liquid sample 8 adhere to the beads of the resin, and at least a portion of the beads with the interfering components attached or the beads without the interfering components attached settle in the mixing cup 16, occupying the bottom 22 of the mixing cup 16. As a result of the settling of the beads with the interfering components attached, a purified liquid sample is formed that occupies the upper portion 24 of the mixing cup 16 and does not contain the interfering components or has them only at a lower concentration than the liquid sample 8. The purified liquid sample occupying the upper portion 24 of the mixing cup 16 is provided for later application of a selected amount of the purified liquid sample that does not contain the interfering components or has them only at a low concentration to the test assay 18.

[0062] Preferably, the predetermined time for allowing the mixed sample / resin solution in the mixing cup 16 to stand is between about 1 minute and about 15 minutes. Further, the resin preferably includes at least one of agarose beads and silica beads. Also, preferably, the assay 18 is a bile acid assay, and the interfering component of the liquid sample is hemoglobin.

[0063] Furthermore, the resin is freeze-dried in a solution of about 2 percent (2%) to about 10 percent (10%) dextran and about 2 percent (2%) to about 10 percent (10%) sucrose, or the resin is freeze-dried in a solution of about 2 percent (2%) to about 14 percent (14%) dextran / sucrose.

[0064] In yet another form of the invention, the resin in the mixing cup 16 is freeze-dried to form a physically stable cake 20, and the resin cake 20 is located within the internal space 38 of the mixing cup 16. Further, the mixing cup 16 further includes a bottom 22 and an upper portion 24 located above the bottom 22. The resin cake 20 re-suspends into a liquid form when the liquid sample 8 is added to the mixing cup 16 to form a sample / resin solution within the mixing cup 16. When the sample / resin solution within the mixing cup 16 is mixed, a mixed sample / resin solution is achieved. When the mixed sample / resin solution within the mixing cup 16 is allowed to stand for a predetermined time, at least a portion of the interfering component of the liquid sample 8 adheres to the beads of the resin, and at least a portion of the beads with the interfering component attached or beads without the interfering component attached settle in the mixing cup 16, occupying the bottom 22 of the mixing cup 16. As a result of the settlement of the beads with the interfering component attached, a purified liquid sample is formed that occupies the upper portion 24 of the mixing cup 16 and does not contain the interfering component or has it only at a lower concentration than the liquid sample 8. The purified liquid sample occupying the upper portion 24 of the mixing cup 16 is provided for later application of a selected amount of the purified liquid sample that does not contain the interfering component or has it only at a low concentration to the assay 18.

[0065] Preferably, the resin is lyophilized in a solution of about 2 percent (2%) to about 10 percent (10%) dextran and about 2 percent (2%) to about 10 percent (10%) sucrose, or the resin is lyophilized in a solution of about 2 percent (2%) to about 14 percent (14%) dextran / sucrose.

[0066] Furthermore, the predetermined time for allowing the mixed sample / resin solution in the mixing cup 16 to stand is between about 1 minute and about 15 minutes, and the resin includes at least one of agarose-based beads and silica-based beads.

[0067] Also, the test assay 18 may be a bile acid assay, and the interfering component of the liquid sample 8 may be hemoglobin.

[0068] In yet another form of the present invention, the mixing cup 16 used to mix the liquid sample 8 in the chemical analyzer 2 includes an internal space 38, a bottom 22, an upper portion 24 located above the bottom 22, and a resin that contains beads and is used by the chemical analyzer 2 to remove components of the liquid sample 8 that may interfere with the test performed by the chemical analyzer 2 for the test assay 18. The resin is located within the internal space 38 of the mixing cup 16. Preferably, the resin is an IMAC (immobilized metal affinity chromatography) resin.

[0069] Preferably, the resin is lyophilized in a solution of about 2 percent (2%) to about 10 percent (10%) dextran and about 2 percent (2%) to about 10 percent (10%) sucrose, or about 2 percent (2%) to about 14 percent (14%) dextran / sucrose to form a physically stable cake 20, the resin cake 20 being located at the bottom 22 of the mixing cup 16, the resin cake 20 resuspending in liquid form when the liquid sample 8 is added to the mixing cup 16 to form a sample / resin solution in the mixing cup 16, a mixed sample / resin solution being achieved when the sample / resin solution in the mixing cup 16 is mixed, and when the mixed sample / resin solution in the mixing cup 16 is allowed to stand for a predetermined time, at least a portion of the interfering components of the liquid sample 8 adhere to the beads of the resin, at least a portion of the beads with the interfering components adhered or beads without the interfering components adhered settle in the mixing cup 16, occupying the bottom 22 of the mixing cup 16, and as a result of the settling of the beads with the interfering components adhered, a purified liquid sample is formed occupying the upper portion 24 of the mixing cup 16 that contains no interfering components or has them only at a lower concentration than the liquid sample 8, the purified liquid sample occupying the upper portion 24 of the mixing cup 16 being provided for later application of a selected amount of the purified liquid sample that contains no interfering components or has them only at a low concentration to the assay 18.

[0070] Furthermore, the present invention relates to a centrifuge cup 12 of a blood separator 14 that forms part of a chemical analyzer 2, which is used to centrifuge a blood sample 8 housed therein to provide separated blood components within the centrifuge cup 12 and has an internal space 40. Preferably, the centrifuge cup 12 contains porous beads and includes an IMAC (immobilized metal affinity chromatography) resin that is used by the chemical analyzer 2 to remove components of the blood sample 8 that may interfere with the tests performed on the test assay 18 by the chemical analyzer 2, and this IMAC resin is located within the internal space 40 of the centrifuge cup 12. The IMAC resin can be present in the internal space 40 of the centrifuge cup 12 in a liquid form, a dried form adhering to the walls of the centrifuge cup 12, or as a physically stable cake 20, as will be described later.

[0071] More specifically, the centrifuge cup 12 of the blood separator 14 contains porous beads and includes an IMAC (immobilized metal affinity chromatography) resin used by the chemical analyzer 2 to remove components of the separated blood components that may interfere with the tests performed on the test assay 18 by the chemical analyzer 2. The IMAC resin is lyophilized in a solution of about 3.5 percent (3.5%) dextran and about 3.5 percent (3.5%) sucrose to form a physically stable cake 20, and this resin cake 20 is located in the internal space 40 of the centrifuge cup 12. The resin cake 20 re-suspends in liquid form when the separated blood components are present in the centrifuge cup 12 to form a blood component / resin solution in the centrifuge cup. When the blood component / resin solution in the centrifuge cup 12 is mixed, a mixed blood component / resin solution is achieved. When the mixed blood component / resin solution in the centrifuge cup 12 is allowed to stand for a predetermined time, at least a portion of the interfering components of the blood components adhere to the porous beads of the IMAC resin, and at least a portion of the porous beads with the interfering components attached or the porous beads without the interfering components attached settle in the centrifuge cup 12 and occupy the bottom 28 of the internal space 40 of the centrifuge cup 12. As a result of the settling of the porous beads with the interfering components attached, a purified blood component is formed that occupies the upper portion 30 of the centrifuge cup 12 and contains no interfering components or only has them at a concentration lower than that of the blood sample 8. The purified blood component that occupies the upper portion 30 of the centrifuge cup 12 is provided for later application of a selected amount of the purified blood component that contains no interfering components or only has them at a low concentration to the test assay 18.

[0072] Figures 8A and 8B illustrate another method for removing the interfering components of a liquid sample according to the present invention. The functionalized beads or particles 41 can be formed to have a magnetic or iron component, or more generally, can be formed to be magnetically attracted to a permanent magnet 42 located within the lower portion 22 of the mixing cup 16 as shown in Figure 8A, or a permanent magnet or electromagnet 44 disposed outside the cup 16, preferably below the bottom, as shown in Figure 8B. The cup 16 formed of a non-magnetic, preferably thermoplastic material, does not interfere with the magnetic attraction between the functionalized magnetic particles or beads 41 and the magnet or electromagnet 42, 44 located inside the cup 16 or adjacent to the cup 16 outside the cup 16.

[0073] The functionalized particles 41 can be in a dried form and coated on the walls of the mixing cup 16, or can be in a physically stable form 20 as already described herein and shown in Figure 6 of the drawings and be present within the cup 16.

[0074] When the liquid sample 8 is added to the mixing cup 16, the functionalized magnetic particles 41 rehydrate and mix with the liquid sample 8 in solution. The interfering components of the liquid sample 8 to be removed adhere to the functionalized magnetic particles 41, and the functionalized magnetic particles 41 are magnetically attracted to the magnet 42, 44 located within the lower portion 22 of the cup 16 or adjacent to the bottom of the cup 16 below the cup 16. In this way, the particles or beads 41 to which the interfering components are attached, or the particles or beads 41 to which no sample components are attached, are attracted to the magnets 42, 44 to occupy the lower portion 22 of the cup 16, leaving a liquid sample 8 that does not contain the interfering components or contains them only at a low concentration, occupying the upper portion 24 of the mixing cup 16 and can be easily aspirated to the pipette tip 6 for later application to the chemical reagent test slide 18.

[0075] Suitable functionalized particles having such magnetism are the beads with part number 88831 distributed by Thermo Fisher Scientific Inc. of Waltham, Massachusetts.

[0076] Although mainly described herein that the gel containing the functionalized particles is placed in the mixing cup 16 used by the automatic chemical analyzer 2, it is also conceivable to place the gel in a sample cup, a reagent cup, a centrifuge cup, or any other type of cup or liquid holding container that can be used for removing interfering components in the liquid sample 8 or reducing the concentration of interfering components in the liquid sample 8. It should be understood that the term "mixing cup" used herein and in the claims should be construed to include any of the above-mentioned cups and containers.

[0077] Although exemplary embodiments of the present invention have been described herein with reference to the accompanying drawings, the present invention is not limited to those exact embodiments, and it should be understood that various other changes and modifications can be made by those skilled in the art without departing from the scope or spirit of the present invention.

Claims

1. 1. A mixing cup for use in mixing a liquid sample in a chemical analyzer, comprising: It has an internal space, The present invention relates to a resin containing beads, the resin is used by the chemical analyzer to remove components of the liquid sample that may interfere with tests performed by the chemical analyzer on a testing assay; The resin is freeze-dried to form a physically stable resin cake; The resin cake is located within the interior space of the mixing cup. Mixing cup.

2. 10. The mixing cup of claim 1, wherein the resin is an IMAC (immobilized metal affinity chromatography) resin.

3. a bottom portion and an upper portion located above the bottom portion; Further equipped with 2. The mixing cup of claim 1, wherein the resin cake resuspends in liquid form when the liquid sample is added to the mixing cup to form a sample / resin solution in the mixing cup, and when the sample / resin solution in the mixing cup is mixed, a mixed sample / resin solution is achieved, and when the mixed sample / resin solution in the mixing cup is allowed to stand for a predetermined time, at least a portion of the interfering components of the liquid sample adhere to the beads of resin, and at least a portion of the beads with or without the interfering components settle in the mixing cup and occupy the bottom of the mixing cup, and as a result of the settling of the beads with the interfering components attached, a purified liquid sample is formed occupying an upper portion of the mixing cup that is free of the interfering components or has a lower concentration than the liquid sample, and the purified liquid sample occupying the upper portion of the mixing cup is provided for subsequent application of a selected amount of the purified liquid sample free of the interfering components or has the lower concentration to the testing assay.

4. The mixing cup of claim 3, wherein the predetermined time for the mixed sample / resin solution in the mixing cup to sit is between 1 minute and 15 minutes.

5. The mixing cup of claim 1 , wherein the resin comprises at least one of agarose-based beads and silica-based beads.

6. the test assay is a bile acid assay; The mixing cup of claim 1 , wherein the interfering component of the liquid sample is hemoglobin.

7. 10. The mixing cup of claim 1, wherein the resin is lyophilized in a solution of two percent (2%) to ten percent (10%) dextran and two percent (2%) to ten percent (10%) sucrose.

8. 10. The mixing cup of claim 1, wherein the resin is lyophilized in a two percent (2%) to fourteen percent (14%) dextran / sucrose solution.

9. a bottom portion and an upper portion located above the bottom portion; Further equipped with The resin is lyophilized in a solution of two percent (2%) to ten percent (10%) dextran and two percent (2%) to ten percent (10%) sucrose, or two percent (2%) to fourteen percent (14%) dextran / sucrose to form a physically stable cake, the resin cake being located at the bottom of the mixing cup, the resin cake resuspending in liquid form when the liquid sample is added to the mixing cup to form a sample / resin solution in the mixing cup, a mixed sample / resin solution is achieved when the sample / resin solution in the mixing cup is mixed, and the liquid sample is resuspended in a liquid form when the mixed sample / resin solution in the mixing cup is allowed to stand for a predetermined period of time.

2. The mixing cup of claim 1, wherein at least a portion of the interfering components of the sample adhere to the beads of resin, at least a portion of the beads with or without the interfering components attached settle in the mixing cup and occupy the bottom of the mixing cup, and as a result of the settling of the beads with the interfering components attached, a purified liquid sample is formed occupying an upper portion of the mixing cup that does not contain the interfering components or has the interfering components at a lower concentration than the liquid sample, and the purified liquid sample occupying the upper portion of the mixing cup is provided for subsequent application of a selected amount of the purified liquid sample that does not contain the interfering components or has the interfering components at a lower concentration to the testing assay.

10. 10. The mixing cup of claim 9, wherein the predetermined time period is between 1 minute and 15 minutes.

11. 10. The mixing cup of claim 9, wherein the resin comprises at least one of agarose-based beads and silica-based beads.

12. 10. The mixing cup of claim 9, wherein the resin is an IMAC (immobilized metal affinity chromatography) resin.

13. the test assay is a bile acid assay; 10. The mixing cup of claim 9, wherein the interfering component of the liquid sample is hemoglobin.

14. 10. The mixing cup of claim 9, wherein the interfering component of the liquid sample is a protein.

15. 1. A method for removing components of a liquid sample that may interfere with testing performed on a testing assay using a chemical analyzer having a sample cup, a mixing cup, and a pipette equipped with a disposable pipette tip having a dispensing end and capable of aspirating and dispensing a liquid sample into and from said pipette tip, and capable of applying the liquid sample to a testing assay, comprising: adding the liquid sample containing the interfering components to the sample cup; transferring the liquid sample containing the interfering components from the sample cup to the mixing cup containing resin containing beads, forming a sample / resin solution in the mixing cup with the liquid sample and resin; mixing the sample / resin solution in the mixing cup using the pipette of the chemical analyzer by repeatedly aspirating the sample / resin solution into the pipette tip and then expelling the sample / resin solution from the pipette tip into the mixing cup as necessary to thoroughly mix the sample / resin solution in the mixing cup and achieve a mixed sample / resin solution; allowing the mixed sample / resin solution in the mixing cup to stand for a first predetermined time period selected such that at least a portion of the interfering components of the liquid sample can adhere to the beads of the resin, at least a portion of the beads with or without the interfering components can settle in the mixing cup to occupy the bottom of the mixing cup, and the settling of the beads with the interfering components results in a first stage purified liquid sample occupying an upper portion of the mixing cup that is free of the interfering components or has a first concentration lower than that of the liquid sample; aspirating a predetermined amount of the first stage purified liquid sample occupying the upper portion of the mixing cup from the mixing cup into the pipette tip; allowing the first stage purified liquid sample aspirated into the pipette tip to stand for a second predetermined time selected such that remaining interfering components of the liquid sample in the first stage purified liquid sample at the pipette tip can adhere to the beads of resin remaining in the first stage purified liquid sample at the pipette tip, at least a portion of the remaining beads with or without the interfering components can settle within the pipette tip to form a settling solution occupying the bottom of the pipette tip near the discharge end of the pipette tip, and as a result of the settling of the beads with and without the interfering components, a second stage further purified liquid sample occupying an upper portion of the pipette tip that is free of the interfering components or has only a second concentration of the interfering components lower than that of the first stage purified liquid sample; expelling the sedimentation solution occupying the bottom of the pipette tip from the pipette tip into the mixing cup while leaving the second stage further purified liquid sample in the pipette tip for subsequent application of a selected amount of the second stage further purified liquid sample that is free of the interfering components or has only the second low concentration of the interfering components to the testing assay.

1. A method for removing interfering components of a liquid sample, comprising:

16. 16. The method for removing interfering components of a liquid sample according to claim 15, wherein the first predetermined time period is between 1 minute and 15 minutes.

17. 16. The method for removing interfering components of a liquid sample according to claim 15, wherein the second predetermined time period is between 1 minute and 15 minutes.

18. 16. The method for removing interfering components of a liquid sample as claimed in claim 15, wherein the resin comprises at least one of agarose-based beads and silica-based beads.

19. 16. The method for removing interfering components of a liquid sample as recited in claim 15, wherein the resin is lyophilized in a two percent (2%) to fourteen percent (14%) dextran / sucrose solution.

20. 16. The method for removing interfering components of a liquid sample as described in claim 15, wherein the resin is lyophilized in a solution of two percent (2%) to ten percent (10%) dextran and two percent (2%) to ten percent (10%) sucrose.

21. 16. The method for removing interfering components of a liquid sample as recited in claim 15, wherein the resin is formed as a physically stable cake and located at the bottom of the mixing cup.

22. 16. The method for removing interfering components of a liquid sample according to claim 15, wherein the resin is an IMAC (immobilized metal affinity chromatography) resin.

23. the test assay is a bile acid assay; 16. A method for removing an interfering component of a liquid sample as claimed in claim 15, wherein the interfering component of the liquid sample is hemoglobin.

24. 16. A method for removing interfering components of a liquid sample as claimed in claim 15, wherein the interfering components of the liquid sample are proteins.

25. 1. A method for removing components of a blood sample that may interfere with testing performed on a testing assay using a chemical analyzer having a blood separator and centrifuge cup, a mixing cup, and a pipette with a disposable pipette tip attached thereto and capable of drawing and dispensing liquids into and from said pipette tip and capable of applying liquids to said testing assay, comprising: adding the blood sample containing the interfering components to the centrifuge cup; centrifuging the blood sample in the centrifuge cup using the blood separator of the chemical analyzer to provide separated blood components in the centrifuge cup, the separated blood components including the interfering components; transferring the separated blood components, including the interfering components, from the centrifuge cup to the mixing cup, including a resin including beads, and forming a blood component / resin solution in the mixing cup with the separated blood components and resin; mixing the blood component / resin solution in the mixing cup using the pipette of the chemical analyzer by repeatedly aspirating the blood component / resin solution into the pipette tip and then expelling the blood component / resin solution from the pipette tip into the mixing cup as necessary to thoroughly mix the blood component / resin solution in the mixing cup and achieve a mixed blood component / resin solution; allowing the mixed blood component / resin solution in the mixing cup to stand for a predetermined time selected such that at least a portion of the interfering components of the blood components can adhere to the beads of the resin, at least a portion of the beads with or without the interfering components can settle in the mixing cup to occupy the bottom of the mixing cup, and the settling of the beads with the interfering components results in the formation of a purified blood component occupying an upper portion of the mixing cup that is free of the interfering components or has a lower concentration of the interfering components than the blood components; aspirating a predetermined amount of the purified blood components occupying the upper portion of the mixing cup from the mixing cup into the pipette tip for subsequent application of a selected amount of the purified blood components that are free of, or have only low concentrations of, the interfering components to the test assay; 1. A method for removing components of a blood sample, comprising:

26. 26. The method for removing interfering components of a blood sample according to claim 25, wherein the predetermined time period is between 1 minute and 15 minutes.

27. 26. The method for removing interfering components of a blood sample of claim 25, wherein the resin comprises at least one of agarose-based beads and silica-based beads.

28. 26. The method for removing interfering components of a blood sample of claim 25, wherein the resin is lyophilized in a two percent (2%) to fourteen percent (14%) dextran / sucrose solution.

29. 26. The method for removing interfering components of a blood sample of claim 25, wherein the resin is lyophilized in a solution of two percent (2%) to ten percent (10%) dextran and two percent (2%) to ten percent (10%) sucrose.

30. 26. The method for removing interfering components of a blood sample of claim 25, wherein the resin is formed as a physically stable cake and located at the bottom of the mixing cup.

31. 26. The method for removing interfering components of a blood sample according to claim 25, wherein the resin is an IMAC (immobilized metal affinity chromatography) resin.

32. the test assay is a bile acid assay; 26. A method for removing interfering components of a blood sample as claimed in claim 25, wherein the interfering component of the blood sample is hemoglobin.

33. 26. A method for removing interfering components of a blood sample according to claim 25, wherein the interfering components of the blood sample are proteins.

34. 1. A method for removing components of a blood sample that may interfere with testing performed on a testing assay using a chemical analyzer having a blood separator and centrifuge cup, a mixing cup, and a pipette equipped with a disposable pipette tip having a dispensing end and capable of drawing liquid into and dispensing liquid from said pipette tip and capable of applying liquid to said testing assay, comprising: adding the blood sample containing the interfering components to the centrifuge cup; centrifuging the blood sample in the centrifuge cup using the blood separator of the chemical analyzer to provide separated blood components in the centrifuge cup, the separated blood components including the interfering components; transferring the separated blood components, including the interfering components, from the centrifuge cup to the mixing cup, including a resin including beads, and forming a blood component / resin solution in the mixing cup with the separated blood components and resin; mixing the blood component / resin solution in the mixing cup using the pipette of the chemical analyzer by repeatedly aspirating the blood component / resin solution into the pipette tip and then expelling the blood component / resin solution from the pipette tip into the mixing cup as necessary to thoroughly mix the blood component / resin solution in the mixing cup and achieve a mixed blood component / resin solution; allowing the mixed blood component / resin solution in the mixing cup to stand for a first predetermined time period selected such that at least a portion of the interfering components of the blood components can adhere to the beads of the resin, at least a portion of the beads with or without the interfering components can settle in the mixing cup to occupy the bottom of the mixing cup, and as a result of the settling of the beads with the interfering components, a first stage purified blood component is formed occupying an upper portion of the mixing cup that is free of the interfering components or has a first concentration lower than that of the blood components; aspirating a predetermined amount of the first stage purified blood components occupying the upper portion of the mixing cup from the mixing cup into the pipette tip; allowing the first stage purified blood component aspirated into the pipette tip to stand for a second predetermined time selected such that remaining interfering components of the blood component in the first stage purified blood component at the pipette tip can adhere to the beads of resin remaining in the first stage purified blood component at the pipette tip, at least a portion of the remaining beads with the interfering components attached or the remaining beads without the interfering components attached can settle within the pipette tip to form a settling solution occupying the bottom of the pipette tip near the discharge end of the pipette tip, and as a result of the settling of the beads with the interfering components attached and unattached beads, a second stage further purified blood component occupying an upper portion of the pipette tip that is free of the interfering components or has only a second concentration of the interfering components lower than that of the first stage purified blood component; expelling the sedimentation solution occupying the bottom of the pipette tip from the pipette tip into the mixing cup while leaving the second stage further purified blood component in the pipette tip for subsequent application of a selected amount of the second stage further purified blood component that is free of the interfering component or has only the second low concentration of the interfering component to the testing assay.

1. A method for removing components of a blood sample, comprising:

35. 35. The method for removing interfering components of a blood sample according to claim 34, wherein the first predetermined time period is between 1 minute and 15 minutes.

36. 35. The method for removing interfering components of a blood sample according to claim 34, wherein the second predetermined time is between 1 minute and 15 minutes.

37. 35. The method for removing interfering components of a blood sample of claim 34, wherein the resin comprises at least one of agarose-based beads and silica-based beads.

38. 35. The method for removing interfering components of a blood sample of claim 34, wherein the resin is lyophilized in a two percent (2%) to fourteen percent (14%) dextran / sucrose solution.

39. 35. The method for removing interfering components of a blood sample of claim 34, wherein the resin is lyophilized in a solution of two percent (2%) to ten percent (10%) dextran and two percent (2%) to ten percent (10%) sucrose.

40. 35. The method for removing interfering components of a blood sample of claim 34, wherein the resin is formed as a physically stable cake and located at the bottom of the mixing cup.

41. 35. The method for removing interfering components of a blood sample according to claim 34, wherein the resin is an IMAC (immobilized metal affinity chromatography) resin.

42. the test assay is a bile acid assay; 35. A method for removing interfering components of a blood sample as claimed in claim 34, wherein the interfering component of the blood sample is hemoglobin.

43. 35. A method for removing interfering components of a blood sample according to claim 34, wherein the interfering components of the blood sample are proteins.

44. A resin cake for use by a chemical analyzer to remove components of a liquid sample that may interfere with tests performed by the chemical analyzer on a testing assay, comprising: A physically stable resin cake is formed by lyophilizing the resin containing beads in a solution of two percent (2%) to ten percent (10%) dextran and two percent (2%) to ten percent (10%) sucrose, or two percent (2%) to fourteen percent (14%) dextran / sucrose.

45. The resin cake of claim 44, wherein the resin is an IMAC (immobilized metal affinity chromatography) resin.

46. 1. A centrifuge cup for a blood separator forming part of a chemical analyzer, comprising: used to centrifuge the blood sample contained in the centrifuge cup to provide separated blood components in the centrifuge cup; It has an internal space, The present invention relates to a resin containing beads, the resin is used by the chemical analyzer to remove components of the blood sample that may interfere with tests performed by the chemical analyzer on a testing assay; The resin is freeze-dried to form a physically stable resin cake; the resin cake is located within the interior space of the centrifuge cup; Centrifugation cup.

47. 47. The centrifuge cup of claim 46, wherein the resin is an IMAC (immobilized metal affinity chromatography) resin.

48. 1. A centrifuge cup for a blood separator forming part of a chemical analyzer, comprising: used to centrifuge the blood sample contained in the centrifuge cup to provide separated blood components in the centrifuge cup; It has an internal space, The present invention relates to a resin containing beads, the resin is used by the chemical analyzer to remove components of the separated blood components that may interfere with tests performed by the chemical analyzer on a testing assay; The resin is freeze-dried in a solution of two percent (2%) to ten percent (10%) dextran and two percent (2%) to ten percent (10%) sucrose, or two percent (2%) to fourteen percent (14%) dextran / sucrose to form a physically stable cake, the resin cake being located in the interior space of the centrifuge cup, the resin cake being resuspended in liquid form when the separated blood components are present in the centrifuge cup to form a blood component / resin solution in the centrifuge cup, when the blood component / resin solutions in the centrifuge cup are mixed, a mixed blood component / resin solution is achieved, and the mixed blood component / resin solution in the centrifuge cup is allowed to stand for a predetermined period of time. when the beads are placed in the centrifuge cup, at least a portion of the interfering components of the blood component adhere to the beads of the resin, at least a portion of the beads with the interfering components attached or the beads without the interfering components attached settle in the centrifuge cup and occupy the bottom of the centrifuge cup, and as a result of the settling of the beads with the interfering components attached, a purified blood component is formed that occupies the upper part of the centrifuge cup and does not contain the interfering components or has the interfering components at a lower concentration than the blood sample, and the purified blood component that occupies the upper part of the centrifuge cup is provided for subsequent application of a selected amount of the purified blood component that does not contain the interfering components or has the interfering components at a lower concentration to the test assay.

49. 49. The centrifuge cup of claim 48, wherein the resin is an IMAC (immobilized metal affinity chromatography) resin.

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