DE102014009511A1 - Signal accumulation method for biochemical sensors - Google Patents

Abstract

In biochemical analysis, affinity sensors with immobilized capture molecules on solid supports are often used. Using biochemical complex formation, target analytes are specifically bound and measured by chemical reactions and physical measurement techniques. The new method is intended to improve the quality and reliability of common biochemical analysis methods using electrical and optical measuring principles. According to the invention, customary dynamic measurement methods are repeated and executed several times and optimized by accumulation of the digitized and temporally resolved measured values. The sensitivity of the analyzes increases by a factor of n1 / 2 for n measurements, whereby fluctuations of individual measurements are eliminated. The method can be used in biochemical analysis using known biochemical analysis methods.

Description

Technical area

The invention relates to analytical methods for measuring the complex binding of immobilized biomolecules and uses of the method.

State of the art

The determination of the complex binding of biochemical analytes using the combination of chemical and physical methods is a well-known and widely used method in molecular biology. This technique plays in the detection of both nucleic acids (see. "Applying Genomic and Proteomic Microarray Technology in Drug Discovery", Robert S. Matson, CRC Press, 2004 ) as well as proteins (cf. "Protein Microarray Technology", Dev Kambhampati, Wiley-Interscience, New York., 2004 an important role. Typically, scavenger or probe molecules are immobilized on solid supports and used for the specific binding of analytical targets. The capture or probe molecules then bind existing target molecules by affinity binding. Usually, these scavenger analyte complexes are modified by other complex chemical methods and specifically labeled for physical detection. Well-suited is a so-called enzyme label, which allows to measure the conversion of suitable enzyme substrates in the corresponding enzyme products both with electrical and optical methods (see. T. Vo-Dinh and B. Cullum, "Biosensors and Biochips: Advances in Biological and Medical Diagnostics"Fresenius' Journal of Analytical Chemistry, 2004, p. 540-551 ). Measurement parameters are often the temporal change of a property or the concentration of a substance at the site of biochemical complex formation. Describe a typical application for the electrical detection of DNA and proteins using enzyme-labeled affinity complexes R. Hintsche et. al. in "Fully Electrical Microarrays" in Electrochemistry of Nucleic Acids and Proteins, Editors: E. Palecek, F. Scheller and J. Wang, 2005, Elsevier, Amsterdam, pp. 247-271 , On electric arrays, they measure the increasing concentration of the products of the marker enzymes by means of amperometry. Alternatively, methods without labeling are used for measuring the biochemical complex formation with acoustic, optical, electrochemical and nanostructured physicochemical transducers. For example, changes in electrical properties, such. As the impedance, or the optical properties, such. As the optical interference or the Schwingunsfrequenz or surface plasmon resonance, good and commonly used indicators for determining the binding of analytes to complex molecules ( Review of Transducer Principles for Label-Free Biomolecular Interaction Analysis; Martin Nirschl, Florian Reuter, Janos Vörös; Biosensors 2011, 1, 70-92 ). The measurement methods described so far determine the parameters of the complex formation by means of a single measurement after the corresponding biochemical process has been induced once. In physical research, long weak measurement signals have been amplified by repeated repetition of the measuring process and adding recording. Especially in high-resolution nuclear magnetic resonance spectroscopy, this principle of repeated excitation and recording of the FID (free induction decay) has been optimized by signal accumulation and has become routine for the method. H. Friebolin: One and two-dimensional NMR spectroscopy. 4th edition Wiley-VCH, Weinheim 2006 ).

Object of the invention

The object of the present invention is to provide an efficient and inexpensive method which improves the sensitivity and the reliability of biochemical analysis methods. It should be used for detection methods with optical, electrical Ausleseprinzipien without having to change the biochemical process.

Inventive solution

• • Messung und Aufzeichnung der digitalisierten Werte, die mittels optischer oder elektrischer Detektoren als Ergebnis einer biochemischen Komplexbildung erhalten werden
• • Zwei- oder mehrfache Wiederholung dieser Messvorgänge
• • Akkumulation der Sensorsignale von wiederholten Messvorgängen durch Addition

The object is achieved by providing an optimization method for detecting biochemical complex formation. By means of electrical or optical readout, dynamic processes during the analysis of biochemical assays on solid planar or spherical carriers are detected more sensitively and precisely by the following steps:

• • Measurement and recording of the digitized values obtained by means of optical or electrical detectors as a result of biochemical complex formation
• • Two or more repetitions of these measurements
• • Accumulation of sensor signals from repeated measurements by addition

The idea of the invention lies in the fact that common biochemical analysis methods whose application according to the prior art generates and records only once a sensor signal are optimized by multiply repeating the measurements. In this case, the biochemical process or the signal release n times induced or repeated and this measured electrically or optically. According to the invention the object is achieved in particular by the method according to claim 1 and the dependent method claims. Associated arrangements and variants for Implementation of the method according to the invention are the subject of claims 2 to 6.

• a) Die Messung zeitaufgelöster Signale von biochemischen Sensoren, wie sie typischerweise auf trägergebundenen Affinitätssensoren, häufig auch in Arrayanordnungen, mittels komplexchemischer Methoden und Markierungen erzeugt werden. Solche Signale werden z. B. durch ansteigende Konzentrationen komplexchemischer Marker oder deren Reaktionsprodukte und Messung mit Hilfe physikochemischer Wandler erhalten. Gut geeignet für das erfindungsgemäße Verfahren sind dabei insbesondere Sensoren mit Enzymmarkern, bei denen nach Zuführung ihrer Enzymsubstrate am Ort der trägergebundenen Affinitätskomplexe eine schnelle Erhöhung der Konzentration der durch das Enzym erzeugten Produkte eintritt. Mit einem elektrochemisch arbeitenden Wandler wird dabei der Konzentrationsanstieg der redoxaktiven Enzymprodukte als ein ansteigender amperometrischer Strom während weniger Millisekunden vermessen. Den gleichen Prozess kann man mit optisch aktiven Enzymprodukten durch die ansteigende optische Intensität mittels optischer Wandler vermessen, wobei messtechnisch ebenfalls eine zeitabhängige Strom-Kurve erhalten wird. Im Fall der Messung von Sensorarrays werden je nach Sensorkonstruktion die verschiedenen Arraypositionen sequentiell nacheinander oder parallel gemessen und einzeln und separat die Verfahrensschritte der Erfindung ausgeführt. Die Messung zeitaufgelöster Signale von biochemischen Affinitätssensoren wird oft auch durch direkte Messung einer physikalische Veränderung oder eines Prozesses bei der oder durch die Komplexbildung vorgenommen. Beispielhafte Techniken hierfür sind elektrische Impedanzmessungen, elektrische Messungen mit Schwingquarzen, optische Resonanzmethoden oder auch dynamische nanostrukturierte Biosensoren.
• b) Der biochemische Prozess und/oder die Signalerzeugung und die Aufzeichnung der Signalveränderung werden mehrfach wiederholt. Für den Anwendungsfall der Enzymmarkierung wird dabei nach dem Verfahrensschritt a) das Substrat/Produkt-Gemisch mittels eines Waschvorganges mit Pufferlösung entfernt und dadurch der Affinitätskomplex in den Ausgangszustand versetzt. Mit erneuter Zuführung von Substrat läuft Schritt a) zum wiederholten Male ab und ein neues Sensorsignal wird erzeugt. Die Trägerbindung der Affinitätskomplexe erlaubt das Waschen des Sensors mit geeigneter Pufferlösung und nachfolgendem erneuten Angebot von Substrat als zyklische Reaktionsführung. Die Wiederholungen können so lange fortgeführt werden, bis eine Degradation der Affinitätskomplexe eintritt, d. h. bis diese sich vom Träger abzulösen beginnen oder inaktiviert werden. Die Zahl der möglichen Wiederholungen hängt von der chemischen Natur der Bindung zwischen Träger und Affinitätskomplex, sowie dessen Stabilität ab und liegt typischerweise zwischen 4 bis 1000. Ausschlaggebend für Wiederholungsmessungen bei den markierungsfreien Verfahren ist die Realisierbarkeit einer effektiven Wiederholung des signalgebenden Prozesses. Bei einigen Verfahren ist beispielsweise die Ablösung eines Analyten und/oder Komplexbildungspartners durch gezielte chemische Maßnahmen, wie z. B. Umgebungs- und Pufferbedingungen möglich. Bei anderen Verfahren kann die Messung nach Entfernung oder Ablösung des Analyten und/oder eines Komplexbildungspartners durch Konkurrenzreaktionen oder Verdrängung durch erneute Komplexbildung wiederholt werden.
• c) Addition jeweils gleicher Messpunkte der digitalisierten Sensorsignale bei wiederholten Messvorgängen wie in 1 beispielhaft dargestellt. 1 zeigt ein Strom-Zeit-Diagramm eines biochemischen Sensors, wobei der signalerzeugende chemische oder physikalische Prozess vor der Messung induziert oder während der Messung unterhalten wird. Dazu wird während der ersten Messung 1 ein physikalischer Messwert Y während einer Zeit t sequentiell gemessen, wobei die Messpunkte M1, M2, M3... bis Mm in diesem Anwendungsbeispiel einem Stromanstieg entsprechen, wie er sowohl mit optischen als auch elektrischen Detektoren erhalten wird. Die Messwerte M1 bis Mm werden als digitalisierte Werte an definierten Plätzen in Datenspeichern abgelegt. Die Zahl der Messpunkte ist frei wählbar und wird den biochemischen und messtechnischen Gegebenheiten angepasst. Nach dieser ersten Messung wird der Sensor in die Ausgangssituation zurückversetzt und der signalerzeugende biochemische Prozess wiederholt, wobei die Messung 2 erfasst wird. Der in gleicher Weise gemessene physikalische Messwert Y wird ebenso während der Zeit t gemessen, wobei wiederum Messpunkte M1 bis Mm entstehen. Diese Messwerte M1 bis Mm werden als digitalisierte Werte an den gleichen Plätzen im Datenspeicher zu den denjenigen aus der ersten Messung hinzuaddiert. Auf diese Weise wird zum Wert M1 aus der ersten Messung der Wert M1 aus der zweiten Messung addiert und analog wird mit den Werten M2 bis Mm verfahren. Dieser Prozess aus zyklischer Signalerzeugung und Datenspeicherung wird mit Messung 3 und im Folgenden bis zur Messung n wiederholt. Eine analoge Addition erreicht man durch Speicherung aller Messwerte aus allen n Messungen an separaten Speicherplätzen und Addition aller Messwerte M1 aller n Messungen am Schluß. Nacheinander werden danach alle Messwerte M2 aller n Messungen und fortlaufend alle entsprechenden Messwerte bis Mm in gleicher Weise verarbeitet.

The method according to the invention according to claim 1 comprises the following steps:

• a) The measurement of time-resolved signals from biochemical sensors, as they are typically generated on carrier-bound affinity sensors, often in array arrangements, using complex chemical methods and markers. Such signals are z. As obtained by increasing concentrations of complex chemical markers or their reaction products and measurement by means of physicochemical transducers. Particularly suitable for the method according to the invention are, in particular, sensors with enzyme markers in which, after the introduction of their enzyme substrates at the site of the carrier-bound affinity complexes, a rapid increase in the concentration of the products produced by the enzyme occurs. With an electrochemical converter, the concentration increase of the redox-active enzyme products is measured as an increasing amperometric current during a few milliseconds. The same process can be measured with optically active enzyme products by the increasing optical intensity by means of optical transducers, wherein metrologically also a time-dependent current curve is obtained. In the case of the measurement of sensor arrays, depending on the sensor construction, the different array positions are measured sequentially or in parallel and the method steps of the invention are carried out individually and separately. The measurement of time-resolved signals from biochemical affinity sensors is often also made by direct measurement of a physical change or process during or through complex formation. Exemplary techniques for this are electrical impedance measurements, electrical measurements with quartz crystals, optical resonance methods or dynamic nanostructured biosensors.
• b) The biochemical process and / or the signal generation and the recording of the signal change are repeated several times. For the application of enzyme labeling, the substrate / product mixture is removed by means of a washing process with buffer solution after process step a) and thereby the affinity complex is converted into the initial state. With renewed supply of substrate step a) is repeated again and a new sensor signal is generated. The carrier binding of the affinity complexes allows the washing of the sensor with a suitable buffer solution and subsequent renewed offer of substrate as a cyclic reaction. The repeats may be continued until degradation of the affinity complexes occurs, that is, until they begin to detach from the carrier or are inactivated. The number of possible repeats depends on the chemical nature of the bond between the support and the affinity complex, as well as its stability, and is typically between 4 and 1000. Crucial for repeat measurements in the label-free methods is the feasibility of an effective repetition of the signaling process. In some methods, for example, the replacement of an analyte and / or complexing partner by targeted chemical measures such. B. Ambient and buffer conditions possible. In other methods, the measurement may be repeated after removal or separation of the analyte and / or a complexing partner by competing reactions or displacement by recomplexing.
• c) Addition of the same measuring points of the digitized sensor signals in repeated measuring operations as in 1 exemplified. 1 shows a current-time diagram of a biochemical sensor, wherein the signal-generating chemical or physical process is induced before the measurement or maintained during the measurement. For this purpose, during the first measurement 1, a physical measured value Y is measured sequentially during a time t, wherein the measuring points M1, M2, M3... To Mm in this example of application correspond to a current increase as obtained with both optical and electrical detectors. The measured values M1 to Mm are stored as digitized values at defined locations in data memories. The number of measuring points is freely selectable and adapted to the biochemical and metrological conditions. After this first measurement, the sensor is returned to the initial situation and the signal-generating biochemical process is repeated, the measurement 2 being detected. The measured physical value Y in the same way is also measured during the time t, whereby in turn measuring points M1 to Mm are produced. These measured values M1 to Mm are added as digitized values at the same places in the data memory to those from the first measurement. In this way, the value M1 from the second measurement is added to the value M1 from the first measurement, and the values M2 to Mm are analogously traversed. This process of cyclic signal generation and data storage is repeated with measurement 3 and subsequently to measurement n. An analogue addition can be achieved by storing all measured values from all n measurements in separate memory locations and adding them all together Measurements M1 of all n measurements at the end. Afterwards, all measured values M2 of all n measurements and consecutively all corresponding measured values up to Mm are processed in the same way.

Through the method, summation values are obtained for the measuring points, which can be described with the following formula. Y _i is the single signal value of a measuring point at the i-th repetition.

Damit erreicht man durch die Anwendung des erfindungsgemäßen Verfahrens schon bei kleinen Wiederholungsraten von z. B. n = 9 eine für biochemische Sensoren bedeutende Signalverstärkung um etwa den Faktor 3 und bei n = 25 um etwa den Faktor 5. Mit dem erfindungsgemäßen Verfahren läßt sich entsprechend Anspruch 6 durch eine Bewertung des korrekten Ablaufes jeder einzelnen Wiederholungsmessung eine weitere Qualitätsverbesserung realisieren. Da biochemische Sensoren und insbesondere Arrayanordnungen oft in fluidischen oder mikrofluidischen Systemen angewandt werden, sind Störungen z. B. durch Gasblasen im Kanalsystem oder auf der Oberfläche von Biochips nicht auszuschließen. Erkennt man im Anwendungsbeispiel z. B. eine Störung des korrekten Ablaufs bei einer der wiederholten 10 Messungen mit Hilfe einer automatisierten Bewertung der Signale, läßt sich diese Messung aussondern bzw. ignorieren. Es werden in diesem Fall nur die verbliebenen restlichen und korrekten Wiederholungsmessungen verwertet. Im Gegensatz zur bisher üblichen Einzelmessung an einem Sensor, die bei einem solchen fluidischen oder auch andersartigen Fehler nicht verwertbar ist, gestattet das erfindungsgemäße Verfahren die Verwertung der Gesamtmessung und verbessert die Qualität. Insgesamt wird dadurch ein qualitativer und ökonomischer Nutzen realisiert.The signal quality increases significantly with the number of repetitions of the measurements achieved. The signal amplitude S increases after n measurements by the factor n, while the noise amplitude N increases but only with half the power of n. As is known, for the improvement of the signal-to-noise ratio:

This can be achieved by the application of the method according to the invention even at low repetition rates of z. B. n = 9 for biochemical sensors significant signal gain by about a factor of 3 and at n = 25 by about the factor 5. With the inventive method can be realized according to claim 6 by evaluating the correct sequence of each repeat measurement a further quality improvement. Since biochemical sensors and in particular array arrangements are often used in fluidic or microfluidic systems, disorders z. B. by gas bubbles in the channel system or on the surface of biochips not exclude. If one recognizes in the application example z. If, for example, a fault in the correct sequence of one of the repeated 10 measurements by means of an automated evaluation of the signals, this measurement can be eliminated or ignored. In this case, only the remaining remaining and correct repetition measurements are utilized. In contrast to the previously customary individual measurement on a sensor which is not usable in such a fluidic or other type of error, the inventive method allows the utilization of the overall measurement and improves the quality. Overall, this results in a qualitative and economic benefit.

embodiment

Other features and advantages of the present invention will become apparent from the following example description and description taken in conjunction with the 1 and the 2 , It shows the basic idea of the method according to the invention using commercially available electrical biochip arrays ( R. Hintsche et. al. in "Fully Electrical Microarrays" in Electrochemistry of Nucleic Acids and Proteins, Editors: E. Palecek, F. Scheller and J. Wang, 2005, Elsevier, Amsterdam, pp. 247-271 ). The work describes the structure and function of the signaling affinity sensors in detail. Of importance for the application of the method according to the invention is the connection of the sensor components to the sensor surface. Silicon chips are used here, the delimited array positions being formed by a structured coating with gold. When used as a nucleic acid sensor, different nucleotide sequences are bound as catcher molecules with a thiol group located at the end of the chain molecules on the gold surfaces of the individual array positions of the chip. These sulfur-gold bonds are of decisive influence on the number of possible repetitions of the measurements by the method according to the invention. The capture molecules then bind their respective target nucleic acids in a position-specific manner according to the usual lock-key principle and can thus be identified. The construction of a signal-generating molecular complex is routinely carried out by enzyme labeling with alkaline phosphatase ( B. Elsholz et al., "Automated detection and quantitation of bacterial RNA by using electrical microarrays" Anal. Chem. 2006, 78, pp. 4794-4802 ). Here, the electro-active p-aminophenol is measured with interdigital electrodes on each array position, which is generated site-specifically by enzyme labeling with alkaline phosphatase after formation of affinity complexes. With an automated multi-channel potentiostat, the individual electrodes are measured sequentially on array positions with multiplexing. The measurement tracks the dynamic process of increasing the concentration of p-aminophenol formed by the marker enzyme at the measuring position. The local detection of the redox molecules formed is achieved by spatial proximity and the high speed of the measurement, during which they have not yet diffused away in the liquid above the sensor. The array sensor is a microfluidic cartridge with inlet and outlet, which allow to automatically feed different liquids.

• 1) Der elektrische Arraysensor mit enzymmarkierten Affinitätskomplexen wird über die Fluidikkartusche mit Phosphatpuffer pH 6,8 gespült und mit dem Multipotentiostaten vermessen. Dies definiert den amperometrischen Strom zum Zeitpunkt t₀ und den Y-Wert des Messpunktes M0 für eine einzelne Arrayposition. Durch übliches elektrisches Multiplexing werden entsprechende Messwerte für jede einzelne Arrayposition gewonnen. Für jede Arrayposition wird dabei ein separates Messdiagramm entsprechend der 1 angelegt, welches in 2 beispielhaft als Arrayposition A und Arrayposition B bezeichnet sind.
• 2) Das gleiche Array wird danach mit einer 1 mM Lösung para-Amino-phenylphospat in Phosphatpuffer pH 6,8 überspült. Das Markerenzym alkalische Phophatase spaltet daraufhin die Aminogruppe seines Substrates ab und die Konzentration an para-Aminophenol steigt lokal an jenen Arrayelektroden an, auf welchen sich enzymtragende Affinitätskomplexe gebildet haben. Die Messung erfolgt in gleicher Weise wie vorstehend angegeben amperometrisch. Die Messwerte zeigen quantitativ die jeweilige Menge an. Gemäß Verfahrensschritt a) werden nun an jeder Arrayposition 20 Messpunkte sequentiell im zeitlichen Abstand von 80 msec gewonnen, wobei dann der physikalische Messwert Y in 1 einer Skala von ca. 100 mA entspricht. Damit ist Messung 1 mit m = 20 Messpunkten erfasst und wird jeweils in das Messdiagramm der jeweiligen Arrayposition eingetragen. Der Anstieg der Kurven entspricht quantitativ der Menge der Affinitätskomplexe auf der jeweiligen Arrayposition.
• 3) Zur Wiederholung wird der Sensor erneut mit Phosphatpuffer pH 6,8 gespült und damit das Substrat und das Produkt der Messung 1 entfernt. Damit stellt man die Ausgangssituation für Messung 2 ein und misst diese mit dem Multipotentiostaten wie vorstehend unter 1). Dies definiert für die Messung 2 den amperometrischen Strom zum Zeitpunkt t₀ und den Y-Wert des Messpunktes M0. Es wird weiter verfahren wie unter Schritt 2) beschrieben und damit die Messung 2 realisiert.
• 4) Die Messwerte M0 bis Mm von Messung 2 werden jeweils zu den Messwerten M0 bis Mm der Messung 1 hinzuaddiert.
• 5) Schritt 1), Schritt 2), Schritt 3) und Schritt 4) werden nacheinander noch 14× bis zur Messung n = 16 wiederholt. Damit erreicht man eine 16-fache Verbesserung der Signalamplitude und eine ca. vierfache Verbesserung des Signal-Rausch-Verhältnisses der Messkurve verglichen mit der üblichen Einzelmessung.
• 6) Vor der Addition der Messpunkte werden alle 16 Messungen einzeln auf Korrektheit geprüft und bewertet. Erkennt man einzelne der Messungen als fehlerhaft werden diese selektiert und verworfen.

With this sensor and measuring arrangement, the method according to the invention is carried out as follows:

• 1) The electrical array sensor with enzyme-labeled affinity complexes is rinsed via the fluidic cartridge with phosphate buffer pH 6.8 and measured with the multipotentiostat. This defines the amperometric current at time t ₀ and the Y value of the measurement point M ₀ for a single array position. Conventional electrical multiplexing produces corresponding measured values for each individual array position. For each array position, a separate measurement diagram will be used 1 created, which in 2 are exemplified as Arrayposition A and Arrayposition B.
• 2) The same array is then rinsed with a 1 mM solution of para-amino-phenylphosphate in phosphate buffer pH 6.8. The marker enzyme alkaline phosphatase then cleaves the amino group of its substrate and the concentration of para-aminophenol increases locally to those array electrodes on which enzyme-bearing affinity complexes have formed. The measurement is carried out in the same way as stated above amperometrically. The measured values indicate quantitatively the respective quantity. According to method step a), measurement points are now obtained sequentially at an interval of 80 msec at each array position, in which case the physical measured value Y in 1 corresponds to a scale of about 100 mA. Thus, measurement 1 with m = 20 measurement points is detected and is entered in the measurement diagram of the respective array position. The increase in the curves corresponds quantitatively to the amount of affinity complexes at the respective array position.
• 3) To repeat, rinse the sensor again with phosphate buffer pH 6.8 and remove the substrate and the product of measurement 1. This sets the starting situation for measurement 2 and measures it with the multipotentiostat as in 1) above. This defines for the measurement 2 the amperometric current at time t ₀ and the Y value of the measuring point M0. The procedure is as described under step 2) and thus the measurement 2 is realized.
• 4) The measured values M0 to Mm of measurement 2 are added to the measured values M0 to Mm of the measurement 1, respectively.
• 5) step 1), step 2), step 3) and step 4) are repeated in succession 14 × until the measurement n = 16. This achieves a 16-fold improvement in the signal amplitude and an approximately fourfold improvement in the signal-to-noise ratio of the trace compared to the usual single measurement.
• 6) Before adding the measuring points, all 16 measurements are individually checked for correctness and evaluated. If one recognizes some of the measurements as faulty, these are selected and rejected.

For the described embodiment with thiol-bound capture molecules, a reduction in the y values of the measurement points M1 to M20 is observed after more than about 20 repetitions. This is due to an initial detachment of the affinity complexes from the sensor. In contrast, biochemical sensors are used in which the capture molecules covalently z. B. are bound via amino or carboxyl or aldehyde groups to the carrier or sensor surface, the number of repetitions can be significantly increased. This achieves improvements in the signal-to-noise ratio> 10. The above example of application for electrical biochips can also be carried out for the exemplary embodiment with optical measured value detection by the local optical intensity z. B. after cleavage of p-nitrophenol by alkaline phosphatase is measured. The repeated measurement of a local optically active fluorescent label can be carried out in an analogous manner.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• "Applying Genomic and Proteomic Microarray Technology to Drug Discovery", Robert S Matson, CRC Press, 2004 [0002]
• "Protein Microarray Technology", Dev Kambhampati, Wiley-Interscience, New York., 2004 [0002]
• T. Vo-Dinh and B. Cullum, "Biosensors and Biochips: Advances in Biological and Medical Diagnostics"Fresenius' Journal of Analytical Chemistry, 2004, p. 540-551 [0002]
• R. Hintsche et. al. in "Fully Electrical Microarrays" in Electrochemistry of Nucleic Acids and Proteins, Editors: E. Palecek, F. Scheller and J. Wang, 2005, Elsevier, Amsterdam, pp. 247-271 [0002]
• Review of Transducer Principles for Label-Free Biomolecular Interaction Analysis; Martin Nirschl, Florian Reuter, Janos Vörös; Biosensors 2011, 1, 70-92 [0002]
• H. Friebolin: One and two-dimensional NMR spectroscopy. 4th edition Wiley-VCH, Weinheim 2006 [0002]
• R. Hintsche et. al. in "Fully Electrical Microarrays" in Electrochemistry of Nucleic Acids and Proteins, Editors: E. Palecek, F. Scheller and J. Wang, 2005, Elsevier, Amsterdam, pp. 247-271 [0009]
• B. Elsholz et al., "Automated detection and quantitation of bacterial RNA by using electrical microarrays" Anal. Chem. 2006, 78, pp. 4794-4802 [0009]

Claims (6)

Signal accumulation method for carrier-based biochemical sensors characterized by: a) Measurement and storage of the signals of complex formation processes and / or derived reactions b) Two or more repetitions of these measurements c) Accumulation of the sensor signals from repeated measurements Process according to Claim 1, characterized in that affinity-binding molecules are immobilized on support materials and optical detection principles are used for complex formation processes. Process according to Claim 1, characterized in that affinity-binding molecules are immobilized on support materials and electrical detection principles are used for complex formation processes. A method according to claim 1, characterized in that affinity-binding molecules are immobilized on array or nano-structured systems and electrical detection principles are used for complex formation processes. A method according to claim 1, characterized in that affinity-binding molecules are immobilized on array or nano-structured systems and optical detection principles are used for complex formation processes. Method according to claim 1 and 2, characterized in that repeated measurements are evaluated according to quality criteria and individual ones thereof are negated, if necessary.

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