A system for performing immunoassay

Abstract

A system (100) for performing immunoassay is provided. The system (100) includes a luminometer ring (102) including a plurality of cuvette holders. Each cuvette holder (104) of the plurality of cuvette holders accommodates a cuvette (106) containing a test sample and a light generating reagent. The light generating reagent reacts with the test sample and results in emission of light through the cuvette (106). The system further includes an optical detector (112) positioned in front of an opening of the luminometer ring (102). The optical detector (112) is configured to receive the light emitted through the cuvette (106) for determining one or more parameters of the test sample. An inner surface of each cuvette holder (104) has a reflective element (114) for directing the light towards the optical detector (112).

Description

SYSTEM FOR PERFORMING IMMUNOASSAYFIELD

[0001] The present embodiments relate to medical equipment. More specifically, the present embodiments relate to a medical equipment for performing immunoassay.BACKGROUND

[0002] Many medical conditions may be diagnosed by sophisticated testing, such as an immunoassay. An immunoassay is a biochemical test that measures presence or concentration of an analyte in a body fluid through use of an antibody or an antigen. One way of performing a biochemical test is by use of an immunoassay analyzer. Generally, the immunoassay analyzer is a luminometer that measures very low-levels of light generated by a test sample undergoing a chemical reaction with a reagent capable of displaying Chemiluminescence (CL) and / or other reagents. The reagents include molecules that bond with the analyte to emit light, such as Acridinium Ester molecules. Each reagent bonds with a specific analyte present in the test sample, such as a blood sample taken from a patient. The test sample and the reagents are combined with a solid-phase medium in a reaction vessel, such as a cuvette or a test tube. The solid-phase medium provides sites for binding of the test sample with the reagents. The light emitted by the chemical reaction of the test sample and the reagent in the cuvette is received and measured by a light detecting device, such as a photomultiplier tube (PMT), for identification of quantity of an analyte present in the test sample.

[0003] For accurate determination of an analyte present in a test sample, a sufficient amount of light is to be collected. However, the PMT is able to collect and measure only a portion of the light directed towards itself from the cuvette. Therefore, the PMT does not receive a sufficient amount of light for accurate determination of the chemical constituents present in the test sample. To address the above-mentioned challenges, conventional luminometers utilize large volume of test samples and the reagents for generating a sufficient amount of light. In this manner, consumption and cost associated with each test sample and the reagents remain high.

[0004] Therefore, there is a need of a system for performing immunoassay that addresses the above-mentioned shortcomings of conventional luminometers.SUMMARY AND DESCRIPTION

[0005] The scope of the present invention is defined solely by the appended claims and is not affected to any degree by the statements within this summary.

[0006] The present embodiments may obviate one or more of the drawbacks or limitations in the related art. For example, a system for performing immunoassay is provided.

[0007] As another example, optical efficiency of a luminometer is increased.

[0008] As yet another example, optical efficiency of a luminometer is increased with minimal changes in its existing shape or design.

[0009] As another example, volume of test samples and reagents required for conducting the immunoassay is reduced.

[0010] As another example, the cost of performing immunoassay is reduced.

[0011] Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

[0012] In one embodiment, a system for performing immunoassay is described. The system includes a luminometer ring having of a plurality of cuvette holders. Each cuvette holder of the plurality of cuvette holders accommodates a cuvette containing a test sample and a light generating reagent. The light generating reagent reacts with the test sample and results in emission of light through the cuvette. The sy stem further includes an optical detector placed in front of an opening of the luminometer ring. The optical detector is configured to receive the light emitted through the cuvette for determining one or more parameters of the test sample. An inner surface of each cuvette holder has a reflective element for directing the light towards the optical detector.

[0013] In one aspect, the reflective element is positioned at a bottom surface and lateral surface of each cuvette holder.

[0014] In one aspect, the reflective element is positioned at a bottom surface, a back surface, a left surface, and a right surface of each cuvette holder.

[0015] In one aspect, the reflective element is a reflective tape, a mirror, reflective paint, a shiny metal surface, or a treated surface.

[0016] In one aspect, the optical detector may be a photomultiplier tube (PMT), a silicon photomultiplier (SiPM), an avalanche photodiode (APD), or a single-photon avalanche photodiode (SPAD).

[0017] In one aspect, the cuvette may be made of a transparent material.

[0018] In one aspect, the transparent material may be glass or Teflon®.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings constitute a part of the description and are used to provide further understanding of the present invention. Such accompanying drawings illustrate the embodiments of the present invention that are used to describe the principles of the present invention. The embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to "arT or "one " embodiment are not necessarily to the same embodiment, and provide at least one. In the drawings:

[0020] Figure 1 illustrates a top view of a luminometer for detecting light emitted from a test sample, in accordance with an embodiment;

[0021] Figure 2 illustrates a front view of the luminometer, in accordance with an embodiment;

[0022] Figure 3(a) illustrates a comparative analysis of amount of light received at a PMT when Thyroid Stimulating Hormone 3-Ultra assay kit was used in different concentrations with and without usage of reflective elements, in accordance with an embodiment;

[0023] Figure 3(b) illustrates a comparative analysis of amount of light received at a PMT when Troponin I Ultra assay kit was used in different concentrations with and without usage of reflective elements, in accordance with an embodiment;

[0024] Figure 4(a) illustrates a plot of light received at the PMT when Troponin I Ultra assay kit was used in different volumes with and w ithout usage of reflective elements, in accordance with an embodiment; and

[0025] Figure 4(b) illustrates a plot of light received at the PMT when Troponin I Ultra assay kit w as used in different volumes with and without usage of reflective elements, in accordance with an embodiment.DETAILED DESCRIPTION

[0026] The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments and is not intended to represent the only embodiments in which the present invention may be practiced. Each embodiment described in this disclosure is provided merely as an example or illustration of the present invention, and should not necessarily be construed as preferred or advantageous over other embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. How ever, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.

[0027] The present embodiments relate to a system for performing immunoassay. The system may be a chemiluminescence immunoassay analyzer utilizing a luminometer for measuring one or more parameters associated with a test sample of a person. The luminometer may include a cuvette holder for accommodating a cuvette cartying the test sample conjugated with reagents, such as a light generating reagent. The luminometer may further include an optical detector for collecting a light generated from a chemiluminescence reaction between the test sample and the light generating reagent. To direct the light towards the PMT, an inner surface of the cuvette holder has a reflective element for directing the light towards the optical detector. The reflective element may be positioned at a bottom surface and side surfaces of each cuvette holder except a side facing the optical detector. The one or more parameters associated with the test sample may be measured based on the amount of light collected by the optical detector.

[0028] Figure 1 illustrates a top view of a luminometer 100 for detecting light emitted from a test sample, in accordance with an embodiment. The luminometer 100 may include a luminometer ring 102 including a plurality of cuvette holders. The luminometer ring 102 maybe a circular insulated track rotatable in a predefined direction. Each cuvette holder 104 of the plurality of cuvette holders may be made of a transparent material such as a glass or plastic. An inner surface of each cuvette holder 104 has a reflective element 114. More specifically, the reflective element 114 may be present at a bottom and three side inner surfaces of each cuvette holder 104. The reflective element 114 may be a reflective paint, a shiny metal surface, or a treated surface. In one implementation, flat mirrors or flat chrome tapes may be mounted at the inner surfaces of each cuvette holder 104. In another implementation, the inner surfaces of each cuvette holder 104 may be coated with a reflective paint.

[0029] Each cuvette holder 104 may discretely accommodate a cuvette 106. Although a cuboidal shape cuvette is illustrated in Figure 1, it is to be understood that the cuvette 106 may be of any other shape, such as a cylindrical shape. Accordingly, the cuvette holders 104 may also be of a cuboidal shape, cylindrical shape, or any other shape. The cuvette 106 may be made of a material transparent to a wide range of wavelengths of light emitted during a chemiluminescence reaction. The cuvette 106 may be made of glass or Teflon®. The cuvette 106 may include a test sample. The test sample may be a blood sample, a urine sample, or a bodily fluid extracted from a human body. The test sample may contain an analyte of interest in form of antigens or antibodies. A light emitting reagent may be added to the cuvette 106. The light emitting reagent may be a type of Acridinium Ester (AE). Successively, other reagents containing antibodies and a solid phase medium are added to the cuvette 106 to form a solution. The solution may be treated, and an acid and a base may then be added in the solutionto generate light by a chemiluminescence reaction between the antibodies present in the other reagents with antigens present in the test sample.

[0030] The cuvette 106 may be placed inside a cuvette holder 104 at an entry position 108 of the luminometer ring 102. In one implementation, a cuvette loader may be used to place the cuvette 106 inside the cuvette holder 104. The luminometer ring 102 may advance the position of the plurality of cuvette holders 104. In one implementation, the luminometer ring 102 may be rotated in a circular direction. The cuvette 106 may be removed from the cuvette holder at an exit position 110 of the luminometer ring 102. In one implementation, a cuvette remover may be used to remove the cuvette 106 from the cuvette holder. When the light emitting reagent reacts with the test sample to emit the light through the cuvette 106, the cuvette 106 may be moved at an opening of the luminometer ring 102.

[0031] The luminometer 100 includes an optical detector 112 positioned (e.g., positioned) in front of the opening of the luminometer ring 102. The optical detector 112 may be a photomultiplier tube (PMT), a silicon photomultiplier (SiPM), an avalanche photodiode (APD). or a single-photon avalanche photodiode (SPAD). In one implementation, the luminometer 100 may include a PMT. The PMT is a highly sensitive light detector that utilizes photoelectric effect combined with secondary emission to convert light into an electrical signal. The PMT may measure light in ultraviolet, visible, and near-infrared ranges of the electromagnetic spectrum. The PMT receives the light emitted from the cuvette 106 through the opening. The reflective element 114 present on the inner surfaces of the cuvette holder 104 directs the light towards the PMT. For an example, when the cuvette holder 104 is cylindrical or spherical shaped, the reflective element 114 may be positioned at a bottom surface and lateral curved surface of each cuvette holder 104. Alternatively, when the cuvette holder 104 is of a cuboidal shape, the reflective element 114 may be positioned at a bottom surface, a back surface, a left surface, and a right surface of each cuvette holder 104. However, it is to be understood that the reflective element 114 is not positioned on a side of the cuvette holder 104 facing the optical detector 112 (e.g., in a direction in which light travels towards the PMT 112). As a majority of light is directed towards the optical detector 112 by use of the reflective elements 114. an amount of the light (e.g.. relative light units (RLUs)) received at the optical detector 112 gets increased. The one or more parameters associated with the test sample are determined based on the amount of light received at the optical detector 112.

[0032] Figure 2 illustrates a front view of the luminometer 100, in accordance with an embodiment. The luminometer 100 includes an opening 202 for allowing the light generated from the test sample to reach the PMT.

[0033] A luminometer with the reflective element 114 and a luminometer without the reflective element 114 were separately utilized to perform immunoassay of a test sample. The immunoassay may be performed using a variety of light emitting reagents. In one implementation, the immunoassay was performed using light emitting reagent corresponding to Thyroid Stimulating Hormone 3-Ultra assay kit and light emitting reagent corresponding to Troponin I Ultra assay kit with different concentrations. The Thyroid Stimulating Hormone 3-Ultra assay kit may include a test sample, a light emitting reagent corresponding to Thyroid Stimulating Hormone 3-Ultra, and other reagents. Similarly, the Troponin I Ultra assay kit may comprise a test sample, a light emitting reagent corresponding to Troponin I Ultra, and other reagents. Counts of RLUs captured by a PMT of a luminometer with the reflective element 114 and a PMT of a luminometer without the reflective element 114 are plotted as illustrated in Figures 3(a), 3(b), 4(a), and 4(b). Specific details shown in the figures and their explanations are provided successively.

[0034] Figure 3(a) illustrates a comparative analysis of amount of light received at a PMT when Thyroid Stimulating Hormone 3-Ultra assay kit was used in different concentrations with and without usage of reflective elements 114. To perform the analysis, Thyroid Stimulating Hormone 3-Ultra assay kit was used in a concentration of OplU / ml and 0. 148plL / ml with and without usage of reflective elements 114. Signal to Noise Ratio (SNR) of 12.89 ± 1.08 was observed when no reflective elements 114 were used. Further, SNR of 12.75 ± 0.73 was observed when reflective elements 114 were used. An increase of at least 170% was observed in a count of RLUs due to usage of the reflective element 1 14 without a change in SNR values.

[0035] Figure 3(b) illustrates a comparative analysis of amount of light received at a PMT when Troponin I Ultra assay kit was used in different concentrations with and without usage of reflective elements 114. To perform the analysis, Troponin I Ultra assay kit was used in a concentration of 0 ng / ml and 0.048 ng / ml with and without usage of reflective elements 114. It w as observed that a count of RLUs gets increased by 204% when Troponin I Ultra assay kit in the concentration of 0 ng / ml is utilized, and the count of RLUs gets increased by 197% when Troponin I Ultra assay kit was used in the concentration of 0.048 ng / ml is utilized. SNR of 5.32 ± 0.50 was observed when no reflective elements 114 were used. Further, SNR of5.18 ± 0.47 was observed when reflective elements 114 were used. An increase of at least 190% w as observed in a count of RLUs due to usage of the reflective element 114 without a change in SNR values.

[0036] Figure 4(a) illustrates a plot of light received at the PMT when Thyroid StimulatingHormone 3-Ultra assay kit was used in different volumes with and without usage of reflective elements 114. To perform the test, Thyroid Stimulating Hormone 3-Ultra assay kit was used in a concentration of 0 plU / ml and 0.148 plU / ml at a standard volume with and without usage of reflective elements 114. Further, the test was performed with a reduced volume and with reflective elements 114 where only 1 / 3 or 33% of the total reaction volume (e.g., all constituents except acid and base) of the Thyroid Stimulating Hormone 3-Ultra assay kit was utilized. It was observed that although the volume was reduced by 2 / 3, a count of the RLUs received by the PMT having reflective elements 114 was equivalent to a count of RLUs received by the PMT having no reflective elements 114. Thus, the total reaction volume gets reduced by 66%. SNR value of 10.55 ± 0.84 was observed when no reflective elements 114 were used. SNR value of 10.83 ± 1.10 was observed when reflective elements 114 were used. Further, SNR value of 9. 10 ± 1.1 1 was observed when reflective elements 1 14 were used with the reduced volume.

[0037] Figure 4(b) illustrates a plot of light received at the PMT when Troponin I Ultra assay kit was used in different volumes with and without usage of reflective elements 114. To perform the test. Troponin I Ultra assay kit was used in a concentration of 0 ng / ml and 0.48 ng / ml at a standard volume with and without usage of reflective elements 114. Further, the test was performed with a reduced volume and with reflective elements 114 where only 1 / 3 or 33% of the total reaction volume (e.g., all constituents except acid and base) of the Troponin I Ultra assay kit was utilized. It was observed that although the volume was reduced by 2 / 3, a count of the RLUs received by the PMT having reflective elements 1 14 was equivalent to a count of RLUs received by the PMT having no reflective elements 114. Thus, the total reaction volume gets reduced by 66%. SNR value of 3.46 ± 0.42 was observed when no reflective elements 114 were used. SNR value of 4.00 ± 0.31 was observed when reflective elements 114 were used. Further, SNR value of 3.62 ± 0.59 was observed when reflective elements 1 14 were used with the reduced volume.

[0038] The above-described embodiments provide a number of technical advancements as mentioned henceforth. A system for performing immunoassay utilizes reflective elements present on inner surfaces of a cuvette holder of a luminometer. The reflective elements direct the light generated by chemiluminescence reaction between a test sample and a light generating reagent towards an optical detector of the luminometer. As a result, a count of RLUs captured by the optical detector is increased with minimal changes in the existing shape or design of the luminometer. Further, volume of the test samples and the reagents required for performing immunoassays in accordance with the present invention is substantially reduced. Thus, morenumber of immunoassays may now be performed using the same volume of test samples and reagents utilized currently for performing the immunoassays. As a result, an overall cost of performing the immunoassays gets reduced. Although the above-mentioned process is described for performing immunoassay, it is to be noted that any assay may be performed using the above-mentioned process.

[0039] In view of the present disclosure, which describes the present invention, all changes, modifications, and variations within the meaning and range of equivalency are considered within the scope and spirit of the invention. It is to be understood that the aspects and embodiment of the disclosure described above may be used in any combination with each other. A number of the aspects and embodiment may be combined together to form a further embodiment of the disclosure.

Claims

WE CLAIM:

1. A system (100) for performing immunoassay, the system comprising: a luminometer ring (102) having a plurality of cuvette holders, each cuvette holder (104) of the plurality of cuvette holders being configured to accommodate a cuvette (106) containing a test sample and a light generating reagent, wherein the light generating reagent reacts with the test sample and results in emission of light through the cuvette (106); and an optical detector (112) positioned in front of an opening (202) of the luminometer ring (102), wherein the optical detector (112) is configured to receive the light emitted through the cuvette (106) for determining one or more parameters of the test sample, wherein an inner surface of each cuvette holder (104) of the plurality of cuvette holders has a reflective element (114) for directing the light towards the optical detector (112).

2. The system (100) of claim 1, wherein the reflective element (114) is positioned at a bottom surface and lateral surface of each cuvette holder (104) of the plurality of cuvette holders.

3. The system (100) of claim 1, wherein the reflective element (114) is positioned at a bottom surface, a back surface, a left surface, and a right surface of each cuvette holder (104) of the plurality of cuvette holders.

4. The system (100) of claim 1, wherein the reflective element (114) is a reflective tape, a mirror, reflective paint, a shiny metal surface, or a treated surface.

5. The system (100) of claim 1, wherein the optical detector (112) is a photomultiplier tube (PMT), a silicon photomultiplier (SiPM), an avalanche photodiode (APD), or a singlephoton avalanche photodiode (SPAD).

6. The system (100) of claim 1, wherein the cuvette (106) is made of a transparent material.

7. The system (100) of claim 6, wherein the transparent material is glass or Teflon®.

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