Biochemical assay with programmable array detection

• US 20030175987A1
• Filed: 03/18/2002
• Published: 09/18/2003
• Est. Priority Date: 03/18/2002
• Status: Active Grant

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: King, David Andrew, Verdonk, Edward, Pittaro, Richard J.
• Granted Patent: US 7,179,654 B2
• Time in Patent Office: Days
• US Class Current: 436/172
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/6454 using an integrated detector array
• CPC Class Codes: Y10T 436/10 Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing

Abstract

A biochemical sensor apparatus having an optical radiation source, a sensor array, and a photodetector array is disclosed. Each sensor of the sensor array includes fluorophores for fluorescence (generating response radiation) when mixed with analytes of interest and exposed to stimulus radiation. An array of photodetectors, such as a CMOS imaging array is used to detect the response radiation. The detected response radiation is converted to digital values and the digital values used to analyze various properties of the analytes present in the sensors.

Claims

1. A method of assaying analytes in a sample, the method comprising:

applying stimulus radiation to a sensor having the analytes and fluorophores, the applied radiation causing the fluorophores to fluoresce generating response radiation;

filtering the response radiation from the sensor, the sensor associated with at least one filter;

imaging the response radiation onto a photodetector array wherein each photodetector of the photodetector array is smaller than the image, the photodetector array having a first subset of photodetectors and a second subset of photodetectors, the photodetector array converting the response radiation into digital values;

determining intensity of the imaged response radiation for each subset of photodetectors; and

calibrating the intensity of the first subset of photodetectors using the intensity of the second subset of photodetectors.

2. The method recited in claim 1 where the photodetector array is a CMOS sensor.

3. A method of assaying analytes in a sample, the method comprising:

applying stimulus radiation to a sensor having the analytes and fluorophores, the applied radiation causing the fluorophores to fluoresce generating response radiation;

filtering the response radiation from the sensor, the sensor associated with at least two polarization filters;

imaging the response radiation onto a photodetector array wherein each photodetector of the photodetector array is smaller than the image, the photodetector array having a first subset of photodetectors and a second subset of photodetectors, the photodetector array converting the response radiation into digital values;

determining intensity of the imaged response radiation for each subset of photodetectors;

calibrating the intensity of the first subset of photodetectors using the intensity of the second subset of photodetectors, the calibration performed by subtracting weighted values of the intensity of the first subset of photodetectors from values of the intensity of the second subset of values; and

determining fluorescence lifetime characteristic.

4. A method of assaying analytes in a sample, the method comprising:

applying stimulus radiation to a sensor having the analytes and fluorophores, the applied radiation causing the fluorophores to fluoresce generating response radiation;

filtering the response radiation;

imaging the response radiation onto a photodetector array wherein each photodetector of the photodetector array is smaller than the image, the photodetector array having a first subset of photodetectors and a second subset of photodetectors, the photodetector array converting the response radiation into digital values;

determining intensity of the imaged response radiation for each subset of photodetectors; and

calibrating the intensity of the first subset of photodetectors using the intensity of the second subset of photodetectors.

5. The method recited in claim 4 where the step of filtering is performed using a color optical filter for determining color distribution of the response radiation and wherein the first subset of photodetectors detects a first color band and the second subset of photodetectors detects a second color band.

6. The method recited in claim 4 further comprising calibrating the response radiation digital value by providing reference fluorophores for the sample, the reference fluorophores being unaffected by the analyte the sensor is designed to measure.

7. The method recited in claim 4 where the stimulus radiation is polarized and where the step of filtering is performed using at least two polarization filters for determining polarization state of the response radiation and wherein the first subset of photodetectors detects a first polarization component of the response radiation, and the second subset of photodetectors detects a second polarization component orthogonal to the first polarization component of the response radiation.

8. The method recited in claim 4 further comprising determining fluorescence lifetime characteristic.

9. The method recited in claim 8 wherein the lifetime characteristic is determined by time staggering the imaging of the responsive radiation by adjacent subsets of the photodetectors.

10. The method recited in claim 8 wherein the lifetime characteristic is determined by repeated sequences of the applying the stimulus radiation and detecting the response radiation.

11. An apparatus comprising:

a sensor including fluorophores for generating response radiation in reaction to stimulus radiation when analyte is present within the sensor; and

a set of detectors for detecting the response radiation from the sensor, the sensor being one sensor in a plurality of sensors, each sensor of the plurality of sensors associated with a unique set of detectors.

12. The apparatus recited in claim 11 wherein the set of detectors is a portion of a CMOS imaging array.

13. The apparatus recited in claim 11 wherein the set of detectors include a first subset of detectors suitable for detecting radiation within a first range of wavelengths, a second subset of detectors suitable for detecting radiation within second range of wavelengths, and a third subset of detectors suitable for detecting radiation within third range of wavelengths.

14. The apparatus recited in claim 11 further comprising a radiation source for providing the stimulus to the sensor.

15. The apparatus recited in claim 11 further comprising a detector unit having a detector array including the set of detectors, the detector unit further comprising additional circuitry for providing digital values representing the response radiation from the sensor.

16. The apparatus recited in claim 15 further comprising a processor for analyzing the digitized values.

17. The apparatus recited in claim 11 wherein the set of detectors include a first subset of detectors suitable for detecting a first polarization component of the response radiation and a second subset of detectors suitable for detecting a second polarization component of the response radiation, the second polarization component being orthogonal to the first polarized component.

18. The apparatus recited in claim 11 wherein the sensor includes at least two fluorophores such that when stimulated, the sample generates the response radiation in several color bands.

19. The apparatus recited in claim 18 wherein the set of detectors includes a first subset for detecting a first color band and a second subset for detecting a second color band.

20. The apparatus recited in claim 19 wherein the sensor includes a reference fluorophore.

21. An apparatus comprising:

radiation source for generating stimulus radiation;

light pipe illuminator for directing the stimulus radiation to a sensor array, the sensor array including an array of sensors, each sensor having fluorophore for generating response radiation in response to the stimulus radiation when analyte is present within the sensor;

a detector array for detecting the response radiation, the detector array including a plurality of detectors grouped in sets, each set associated with a single sensor.

22. The apparatus recited in claim 21 wherein the detector array is a CMOS imaging array.

23. The apparatus recited in claim 21 further comprising a detector unit including the detector array, the detector unit converting the response radiation to digital values.

24. The apparatus recited in claim 23 further comprising a processor for analyzing the digital values.