KR20080085517A - Label-free analysis method of blood proteins with tagged-internal standards and chip technology - Google Patents

Abstract

An analysis method of blood proteins is provided to reduce the analysis time by immediately analyzing the blood proteins through comparison with the pre-labeled standard proteins without labeling process, and rapidly read the analysis results, and simultaneously analyze multiple bloods with one standard sample. An analysis method of blood proteins comprises the steps of: immobilizing an antibody specifically binding to a protein(antibody) to be analyzed to the surface to prepare a protein chip; preparing a labeled standard protein identical to the protein to be analyzed; mixing the standard protein with a sample containing the protein to be analyzed, and spotting the mixture on the surface of the protein chip with antibody; and analyzing the intensity shown by the competitive immune response between the standard protein and the protein to be analyzed against the antibody of the protein chip with a fluorescence scanner. Further, the labeled standard protein is marked by biotin.

Description

Label-free analysis method of blood proteins with tagged-internal standards and chip technology}

1 is a view for explaining the manufacturing process of the protein chip used in the present invention

Figure 2 is a view for explaining the blood protein analysis method of the present invention

Figure 3a is an image showing the fluorescence according to the CRP concentration in normal standard serum

Figure 3b is a graph showing the standard calibration curve according to the CRP concentration in normal standard serum

Figure 4a is an image showing the results of analyzing the amount of CRP on the chip according to the invention in a plurality of blood on the chip

4b is in accordance with the invention in a plurality of blood A graph showing the correlation between the amount of CRP analyzed and the amount of CRP analyzed by turbidity immunoassay

The present invention relates to a method for analyzing unlabeled blood proteins using a competitive interaction based on chip technology, and more particularly, a disease-associated protein present in the blood of a patient such as cardiovascular disease and cancer. The present invention relates to a method for analyzing a sample by using a competitive interaction between a protein to be analyzed and a pre-labeled standard protein without labeling the sample.

The recent genome project predicts about 100,000 human genes, of which about 10,000 functions have been identified, and most of these genes are known to be directly related to disease. In addition, since most diseases are caused at the protein level, not at the genetic level, more than 95% of drugs developed or under development target proteins.

Recently, researches on the development of methods for treating and preventing diseases by analyzing specific proteins in blood or other biological fluids have been actively conducted, and protein chips are mainly researched and developed to measure and analyze specific proteins as described above. have.

Such a protein chip immobilizes a protein such as an antigen or an antibody that can specifically bind to a target protein to be analyzed on a small substrate or slide, and then interacts with a specific protein in an assay sample (mainly an immune response). The specific protein in the sample is analyzed by analyzing the binding result using. In particular, it is useful for analyzing disease-related blood proteins present in the blood of patients such as cardiovascular disease and cancer.

Meanwhile, in analyzing a specific protein based on the protein chip as described above, it is essential to perform a labeling operation in order to distinguish and detect analytes in the analytical sample. Organic dyes and silver stain-based methods, radioactive labeling methods, fluorescence-based staining methods, chemiluminescence-based staining methods) and the like are used.

Among the labeling methods described above, dyeing methods using organic dyes and silver show the limitation of use due to low detection sensitivity and narrow linear dynamic range, and radioisotope labeling methods can cause serious environmental pollution and are expensive. Has its drawbacks. Therefore, recently, the fluorescence staining method having a very high sensitivity and reproducibility is most widely used.

However, the above-described fluorescence staining method requires labeling all proteins in the assay sample with fluorescent dyes, and after labeling, the unlabeled fluorescent dyes must be separated, which requires high analysis cost and long analysis time. In the labeling process, there may be a decrease in activity due to degeneration of the protein, and thus there is a problem that accurate analysis is difficult because of experimental errors. In addition, this experimental error can also occur in the protein separation process, the overall error range in the analytical method becomes large.

As such, conventional labeling methods, including fluorescence staining, have various problems such as high cost, prolonged analysis time, and lack of accuracy due to the labeling of the protein to be analyzed. The research on the unlabeled method that can be done is in progress, but the results of the research are still insufficient.

Therefore, the present invention provides a quick and accurate analysis at a low cost by analyzing a disease-related protein present in the blood based on a protein chip, and through a competitive reaction between a protein to be analyzed and a standard protein labeled in advance. It is an object to provide a method for analyzing this possible unlabeled blood protein.

The present invention to achieve the above object,

Preparing a protein chip by immobilizing an antibody capable of specifically binding to a protein (antigen) to be analyzed;

Preparing a standard protein labeled with the same protein as the protein to be analyzed;

Mixing the standard protein with an assay sample containing the protein to be analyzed and spotting the surface of the protein chip to which the antibody is immobilized;

Analyzing the intensity of the fluorescence (fluorescence scanner) through a competitive immune response between the standard protein and the protein to be analyzed for the antibody of the protein chip; It is achieved by providing a method for analyzing unlabeled blood proteins using a competitive interaction.

Hereinafter, a method for analyzing blood proteins using a competitive interaction according to the present invention will be described in more detail.

In the present invention, in analyzing a disease-related protein present in the blood based on a protein chip, an analysis sample including a protein to be analyzed (hereinafter, referred to as an 'analytical protein') and a protein identical to the analytical protein can be distinguished from each other. Labeled standard proteins were mixed and loaded onto protein chips to analyze the fluorescence (intensity) resulting from competitive immunity between the analyte protein and the standard protein. Provided is a method for analyzing labeled blood proteins.

In analyzing blood proteins as described above, the first step is to prepare a protein chip immobilized on the surface of the antibody that can specifically bind to the assay protein. Such a protein chip is applicable to all protein chips that have been conventionally used, but will be described below with reference to Figure 1 attached to the drawings for a protein chip that can be most usefully used in the present invention.

1 is a view for explaining the manufacturing process of the protein chip used in the present invention.

First, the substrate is immersed in a solution containing 3-aminopropyltrimethoxysilane to introduce 3-aminopropyltrimethoxysilane on the surface of the substrate.

Here, the 3-aminopropyltrimethoxysilane-containing solution is prepared by dissolving 3-aminopropyltrimethoxysilane in an alcohol solvent such as ethanol. The methoxysilane is contained in 1 to 2% by weight, but the concentration is not necessarily limited.

Submersion time of the substrate is sufficient to carry out at least 2 hours, and after about 2 hours, the substrate is washed three times for 5 minutes alternately with ethanol and distilled water, and then dried in an oven at 110 ℃ for 1 hour to the surface of the substrate 3-aminopropyltrimethoxysilane is introduced.

In this case, a metal substrate or a slide glass substrate which is widely used in the art may be used, and the substrate is preferably used after sufficient cleaning. In the present invention, it is used after immersing and washing for 10 minutes in a cleaning solution in which 10 to 40 parts by weight of hydrogen peroxide (H ₂ O ₂ ) and 10 to 40 parts by weight of aqueous ammonia (NH ₄ OH) are mixed for 100 parts by weight.

After introducing the 3-aminopropyltrimethoxysilane to the surface of the substrate through the above steps, and attaching the perforated tape at a predetermined interval to the surface of the substrate introduced with the 3-aminopropyltrimethoxysilane 3 A step of manufacturing an array chip having a plurality of spots exposed to aminopropyltrimethoxysilane is carried out.

The number of spots can be arbitrarily selected according to the size of the substrate or the shape of the spot, and the tape may be a Teflon tape having less reactivity.

As a next step, 3-aminopropyltrimethol is reacted by reacting 3-aminopropyltrimethoxysilane with carboxylate modified latex bead to the spot of the array chip prepared as described above. The latex beads are introduced into the amine group terminal of the oxysilane.

Herein, the carboxyl-modified latex beads may be applied to those generally used in the art, that is, in the field of protein analysis chip, and in the present invention, latex beads having a size of 500 nm are used.

As described above, the introduction of the latex beads is performed to facilitate the introduction of Protein G, which will be described later. When the latex beads modified with a carboxyl group and 3-aminopropyltrimethoxysilane are reacted, the carboxyl group and the amine group are mutually introduced. By the reaction, latex beads are introduced at the terminal of the amine group of 3-aminopropyltrimethoxysilane.

At this time, for more smooth reaction, the carboxyl-modified latex beads are reacted in the presence of N-hydroxysuccinimide and carbodiimide to be activated, and then the reaction solution is added dropwise to the 3-aminopropyltrimethoxysilane layer. It is recommended that the latex bead is introduced to the amine end of 3-aminopropyltrimethoxysilane.

Here, carbodiimide plays a role of activating a carboxyl group as a catalyst to facilitate the substitution of N-hydroxysuccinimide at the carboxyl group (-OH) of the latex beads.

The carbodiimide may be N-ethyl-N '-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) or N, N'-dicyclohexyl carbodiimide (N, N'-dicyclohexyl carbodiimide (DCC) or diisopropylcarbodiimide may be used.

A latex bead modified with a carboxyl group is added to a mixed solution of N-hydroxysuccinimide and carbodiimide, and the solution is added dropwise to 3-aminopropyltrimethoxysilane and left for about 20 minutes. Is done. At this time, the dripping amount may be an amount enough to cover the spot. In the following description, the dripping amount indicates an amount enough to cover the spot. At this time, the addition amount of the carboxyl group-modified latex beads added to the mixed solution of N-hydroxysuccinimide and carbodiimide is not necessarily limited, but in the present invention, the mixture of N-hydroxysuccinimide and carbodiimide 20 to 50 parts by weight of carboxyl-modified latex beads are added to 100 parts by weight of the solution, and more preferably, the same amount of carboxyl-modified latex beads is added to the mixed solution of N-hydroxysuccinimide and carbodiimide. Dilute. together Carbodiimide may be used by mixing N-hydroxysuccinimide with various equivalent ratios, and in the present invention, the mixture is used so as to have an equivalent ratio of 2 to 4: 1, but may be variously changed as necessary. Do.

When the substrate into which the latex beads are introduced is washed with PBST (Phosphate buffered saline with 0.1% Tween 20; a solution prepared by adding 0.1% Tween 20 in phosphate buffered saline) or distilled water, and then dried. Latex beads are introduced into the amine group ends of 3-aminopropyltrimethoxysilane. What is necessary is just to use PBST in the range of pH7.2-7.6 here.

As a next step, protein G is introduced into the latex beads by dropping sodium acetate buffer in which protein G is dissolved on the latex beads introduced as described above, wherein the protein G is an antibody introduced in the next step. A substance that has a binding force with the Fc portion of an antibody.

Thus, introduction of protein G on latex bead is made by reaction of the amine group contained in protein G with the carboxyl group of latex bead. Therefore, to facilitate the introduction of protein G into the latex beads, N-hydroxysuccinimide and carbodiimide mixed solution was added dropwise onto the latex beads to activate the carboxyl groups of the latex beads, and then dissolved in sodium acetate buffer. It is preferable to dripped the thing which melt | dissolved protein G.

Carbodiimide acts as a catalyst as described above, and activates the carboxyl group to facilitate the introduction of protein G into the carboxyl group (-OH) of the latex beads. Similarly, the carbodiimide may be N-ethyl-N '-(3-dimethylaminopropyl) carbodiimide hydrochloride or N, N'-dicyclohexyl carbodiimide (N, N). '-dicyclohexyl carbodiimide (DCC) or diisopropylcarbodiimide may be selected from. In addition, carbodiimide may be used by mixing N-hydroxysuccinimide with various equivalent ratios, and in the present invention, a mixture of 2 to 4: 1 equivalents was used as described above.

As described above, when a mixed solution of N-hydroxysuccinimide and carbodiimide is dropped on the latex beads and left for about 10 minutes, the carboxyl group of the latex beads is activated, and in this state, sodium acetate buffer solution in which Protein G is dissolved. After dropping, the mixture is left for at least 2 hours to introduce protein G into the latex beads, and after two hours, the reaction is completed, washed with PBST or distilled water and dried. At this time, the sodium acetate buffer is used to be prepared in the range of pH 4 ~ 5.

As a next step, a phosphate buffer in which an antibody that specifically binds to the analyte protein (binding through an antigen-antibody reaction) is added dropwise onto the latex beads into which protein G is introduced as described above. By introducing the antibody protein into protein G, the production of the array type protein chip is completed. The protein G has a binding force with the Fc portion of the antibody or antigen and is easily introduced. At this time, the phosphate buffer used is prepared in the range of pH 7 ~ 8, and after the reaction is completed about two hours after the introduction of the antibody and washed with PBST or distilled water and dried.

In this case, in order to increase the accuracy of the analysis, it is preferable to block the empty part of the spot which is not bound with the antibody of the protein chip prepared as described above. This blocking is treated with BSA (Bovine serum albumin), normal serum (normal serum) or skim milk (skim milk). In the present invention, a blocking solution obtained by dissolving 1 to 10% by weight of BSA in PBST (phosphate buffered saline containing Tween 20) is added dropwise and left for 1 hour to block. When the blocking is completed, when washed with PBST or distilled water and dried, the BSA is introduced into the empty part where the antibody is not introduced, and this BSA does not affect the reaction of the steps described later, contributing to improving the analysis accuracy. Done.

An array-type protein chip into which an antibody prepared by performing as described above is introduced is used to analyze a disease-related protein in blood through the steps described below, which will be described below with reference to FIG. 2 attached to the drawings. do.

2 is a view for explaining the protein analysis method of the present invention.

When the protein chip prepared through the above-described process is prepared, a standard protein labeled separately from the analyte protein is prepared on the same protein as the analyte protein. These labels can be fluorescently labeled with fluorescent dyes such as Cy3 (green), Cy5 (red), FITC (green), Alexa, BODIPY, Rhodamine, Q-dot, as well as the well-known Alexa series. It can also be labeled with biotin, which is widely used in. These biotin-bound proteins can be labeled with fluorescence using fluorescent dyes or HRP-bound avidin or analyzed by color reaction.

The standard protein is uniformly placed in a container such as an analyte and a microfuse tube containing the analyte protein. After mixing, the antibody is spotted on the surface of the immobilized protein chip. Although the mixing ratio of the standard protein and the assay sample is not particularly limited, it is preferable to mix in a ratio of 1: 1 to maintain the objectivity of the analysis.

When the mixture of the assay sample and the standard protein mixed as described above is dropped into the spot of the protein chip prepared by the above-described method, the analyte protein and the standard protein are mutually competitive to bind to the antibody immobilized on the protein chip. Will react. That is, the amount of standard protein that can be bound to the protein chip varies according to the content of the analyte protein in the analyte, and thus the intensity of the fluorescence on the protein chip is different depending on the content of the analyte protein in the analyte. .

For example, if the analyte contains less analyte protein, the fluorescence is relatively bright because the labeled protein binds more to the protein chip than the analyte protein. On the contrary, if the analyte contains a large amount of analyte, the fluorescence is somewhat dark because the amount of standard protein bound to the protein chip is reduced.

In this way, by measuring the intensity of the intensity (fluorescence scanner) through the competitive interaction between the standard protein and the assay protein (fluorescence scanner), it is possible to determine the presence and concentration of the analyte protein in the assay sample.

In the above analysis method, if a control table in which the fluorescence is described according to the intensity of the analyte protein was simultaneously produced, the concentration of the analyte protein was compared by analyzing the fluorescence of the protein chip shown in the analysis process with the fluorescence of the prepared control table. Immediate quantitative analysis

The protein analysis method performed through the above described steps can be analyzed in a short time through a competitive reaction with a standard protein that is previously labeled without labeling the entire analyte containing the analyte protein as before, and the result of the analysis is also immediately read. Because of this, the overall analysis time can be drastically reduced, and in particular, multiple blood proteins can be simultaneously tested using a single standard, which is very economical due to the reduction of test cost and analysis time.

In addition, the protein activity is reduced due to the denaturation of proteins that may occur in the process of labeling the conventional analytical sample and the separation of the labeling material in the analytical sample is omitted, thereby solving the problem of error caused by this, more accurate analysis is possible. Done.

The protein analysis method of the present invention as described above is not limited to analyzing various disease-related proteins present in the blood of patients, such as cardiovascular disease, cancer, it is natural that it can be applied to all protein analysis, furthermore urine It can be applied to the analysis of all types of proteins, including intracellular proteins, including biological fluids of humans and animals such as proteins and saliva proteins.

Hereinafter, the present invention will be described in more detail with reference to the following examples, which are only presented to aid the understanding of the present invention, but the present invention is not limited thereto.

<Production example>

Production of Protein Chips

The slide glass was immersed in a solution prepared by dissolving 1.5% by weight of 3-aminopropyltrimethoxysilane in an ethanol solution for 2 hours, washed with ethanol and distilled water, and dried in an oven at 110 ° C. for 1 hour. 3-aminopropyltrimethoxysilane was introduced to the surface. At this time, the slide glass was used by dipping for 10 minutes in a cleaning solution (H ₂ O ₂ : NH ₄ OH: dH ₂ O = 1: 1: 5) at 70 ℃.

A Teflon tape having spots of 1.5 mm in diameter was formed by using a punch on the slide glass surface into which 3-aminopropyltrimethoxysilane was introduced to prepare an array chip having 200 (8 × 25) spots.

500 × 100 nm sized carboxyl-modified latex beads washed with PBS were added to the mixed solution of 200mM EDC and 50mM NHS in the same amount, and then dropped in the spot of the array chip for 20 minutes. After washing with PBS containing 0.1% Tween 20 for 1 hour and then again washed with distilled water for 5 minutes, and dried by blowing air to introduce latex beads to the amine group end of 3-aminopropyltrimethoxysilane.

200mM EDC and 50mM NHS mixed solution was added dropwise to the latex beads and left for 10 minutes, washed with distilled water and dried while blowing air. Then, sodium acetate buffer solution (pH4.5) in which protein G was dissolved at a concentration of 500 µg / ml was added dropwise, and left in an incubator at 37 ° C for 2 hours. After washing with PBS containing 0.1% Tween 20 for 10 minutes, and then again washed with distilled water for 5 minutes, and air dried to introduce Protein G into the latex beads.

Phosphate buffer solution (pH7.4) in which the antibody (anti-CRP) was dissolved at a concentration of 200 µg / ml was added dropwise onto the protein G, and left in an incubator at 37 ° C. for 2 hours, followed by 0.1% Tween 20. After washing with PBS for 10 minutes and again with distilled water for 5 minutes, and then air dried to introduce an antibody (anti-CRP) to the latex beads.

To the latex beads into which the antibody (anti-CRP) was introduced, a blocking solution containing 3% by weight of BSA was added dropwise to PBST (Phosphate buffered saline containing 0.1% by weight Tween 20) and incubated at 37 ° C for 1 hour. After standing, washed with PBS containing 0.1% Tween 20 for 10 minutes, washed again with distilled water for 5 minutes, and air dried to prepare an array type protein chip.

<Example 1>

Unlabeled antigen diluted by concentration with standard protein labeled 1 μg / ml and 5 wt% BSA (phosphate buffered saline containing 0.1 wt% Tween 20) labeled with fluorescent substance Alexa546 on the antigen (CRP) After mixing (CRP) in the same weight ratio to each microfuge tube (microfuge tube), it was added dropwise to the top of the protein chip with the antibody made in the preparation, and left in an incubator at 37 ℃ for 1 hour, Washed with PBS containing 1% Tween 20 for 1 hour, washed again with distilled water for 5 minutes and then air dried. The fluorescence in the spot portion of the protein chip was scanned with a fluorescence scanner (Scan Array Lite; GSI Lumonics. Kanata, Ontario, Canad), and the image thereof is shown in FIG. 3a, and shows a standard calibration curve according to the concentration of antigen. Shown in 3b.

In addition, the analysis sample diluted 10-fold with PBST containing 5% by weight of BSA containing the protein to be analyzed and the standard sample were mixed, and analyzed through a protein chip in the same manner as described above The fluorescence was scanned, and the scanned image is shown in FIG. 4A, and the amount of antigen (CRP) obtained by substituting the standard calibration curve and the concentration turbidity immunoassay of the antigen widely used clinically were analyzed. Comparison of the amount of antigen (CRP) is shown in Figure 4b (n = 69, r = 0.96268, p <0.0001).

As shown here, it can be seen that there is a very high correlation between the amount of antigen (CRP) obtained using the antigen (CRP) analysis system and the amount of antigen (CRP) obtained by the concentration turbidity immunoassay. It can be seen that accurate protein analysis is possible.

As described above, the blood protein analysis method of the present invention can be directly analyzed through a competitive reaction with a standard protein that is pre-labeled without labeling an assay sample containing the protein to be analyzed, and the analysis result can also be read immediately. Therefore, the overall analysis time can be reduced. Especially, since multiple blood can be tested simultaneously with one standard sample, it can bring about very high economic effect due to the reduction of test cost and analysis time.

In addition, the analytical method of the present invention prevents a decrease in protein activity due to protein denaturation that may occur in the process of labeling a conventional analytical sample, and the separation of fluorescent dyes in the analytical sample is omitted, thereby preventing the problem of error. This can have another effect of being able to solve the problem more accurately.

Claims (11)

Preparing a protein chip by immobilizing an antibody capable of specifically binding to a protein (antigen) to be analyzed; Preparing a standard protein labeled with the same protein as the protein to be analyzed; Mixing the standard protein with an assay sample containing the protein to be analyzed and spotting the surface of the protein chip to which the antibody is immobilized; Analyzing the intensity of the fluorescence (fluorescence scanner) through a competitive immune response between the standard protein and the protein to be analyzed for the antibody of the protein chip; Method for analyzing unlabeled blood proteins using a competitive interaction. The method according to claim 1, wherein the protein chip is Immersing the substrate in a solution containing 3-aminopropyltrimethoxysilane to introduce 3-aminopropyltrimethoxysilane to the surface of the substrate; An array chip having a plurality of spots exposed to 3-aminopropyltrimethoxysilane by attaching a perforated tape at predetermined intervals on the surface of the substrate on which the 3-aminopropyltrimethoxysilane is introduced. Preparing a; Reacting the 3-aminopropyltrimethoxysilane of the array chip with a carboxylate modified latex bead to introduce latex beads into the amine end of the 3-aminopropyltrimethoxysilane; Introducing protein G into the latex beads by dropping sodium acetate buffer containing Protein G in the array chip into which the latex beads are introduced; Competitiveness based on the chip technology, characterized in that prepared by the step of dropping a phosphate buffer (phosphate buffer) in which the antibody (protein) dissolved in the array G introduced protein; Analysis of Unlabeled Blood Proteins Using Interactions. The method according to claim 2, Unlabeled blood using competitive interaction based on chip technology comprising introducing an antibody into the array chip and then treating the blank portion of the spot that is not bound with the antibody by blocking with a blocking solution. Analysis of Proteins. The method according to claim 2 or 3, In the step of introducing the latex beads to the amine group terminal of the 3-aminopropyltrimethoxysilane, the carboxyl-modified latex beads are reacted in the presence of N-hydroxysuccinimide and carbodiimide to activate the carboxyl group, followed by reaction A method for analyzing unlabeled blood proteins using a competitive interaction based on chip technology, characterized in that the solution is added dropwise to 3-aminopropyltrimethoxysilane to react. The method according to claim 4, The carbodiimide is N-ethyl-N '-(3-dimethylaminopropyl) carbodiimide hydrochloride or N, N'-dicyclohexyl carbodiimide (DCC) or diiso A method for the analysis of unlabeled blood proteins using a competitive interaction based on chip technology, characterized in that it is selected from diisopropylcarbodiimide. The method according to claim 5, Before introducing the protein G into the latex beads, a mixed solution of N-hydroxysuccinimide and carbodiimide is added dropwise onto the latex beads introduced at the amine group end of 3-aminopropyltrimethoxysilane to form a carboxyl group of the latex beads. Activation and then dropping sodium acetate buffer in which Protein G is dissolved therein. A method of analyzing unlabeled blood proteins using a competitive interaction based on chip technology. The method according to claim 6, The carbodiimide is N-ethyl-N '-(3-dimethylaminopropyl) carbodiimide hydrochloride or N, N'-dicyclohexyl carbodiimide (DCC) or di A method for the analysis of unlabeled blood proteins using a competitive interaction based on chip technology, characterized in that it is selected from isopropylcarbodiimide. The method according to claim 1, The standard protein is fluorescently labeled using one selected from Cy3, Cy5, Alexa, BODIPY, Rhodamine, and Q-dot as well as Alexa series. Analytical Method. The method according to claim 1, The standard protein is biotin (labeled with biotin) characterized in that the analysis of unlabeled blood proteins using a competitive interaction based on chip technology. The method according to claim 8 or 9, The target protein is a disease-associated protein (antigen) present in the blood analysis method of the unlabeled blood protein using a competitive interaction based on chip technology. The method of claim 10, wherein after analyzing the fluorescence intensity of the protein chip by the fluorescence scanner, the concentration of the target protein is calculated by comparing and analyzing the fluorescence according to the concentration of the standard protein prepared according to the intensity. Analysis method of an unlabeled blood protein using a competitive interaction based on the chip technology, characterized in that it comprises a.

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