LED or laser enabled real-time PCR system and spectrophotometer

• US 7,122,799 B2
• Filed: 12/18/2003
• Issued: 10/17/2006
• Est. Priority Date: 12/18/2003
• Status: Expired due to Fees

• Current Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Kneissl, Michael A., Hsieh, Huangpin Ben
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): Sung, Christine
• Application Number:
  US10/739,706
• Publication Number:
  US 20050133724A1
• Time in Patent Office: 1,034 Days
• Field of Search: 250/339.12, 250/339.06, 250/339.07, 250/458.1, 250/461.1, 250/461.2, 319/326
• US Class Current: 250/339.12
• CPC Class Codes: B01L 2300/0654 Lenses; Optical fibres
• CPC Class Codes: B01L 2300/0829 Multi-well plates; Microtitration plates
• CPC Class Codes: B01L 7/52 with provision for submitting samples to a predetermined sequence of different temperatures, e.g. for treating nucleic acid samples amplification or hybridisation processes per se C12Q1/68; controlling sequential reactions for synthesis B01J19/0046
• CPC Class Codes: G01N 21/0303 Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment G01N21/031 - G01N21/15 take precedence
• CPC Class Codes: G01N 21/253 for batch operation, i.e. multisample apparatus analytical automats G01N35/00
• CPC Class Codes: G01N 21/272 for following a reaction, e.g. for determining photometrically a reaction rate (photometric cinetic analysis)
• CPC Class Codes: G01N 21/31 Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry G01N21/72 takes precedence
• CPC Class Codes: G01N 21/33 using ultraviolet light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/6452 Individual samples arranged in a regular 2D-array, e.g. multiwell plates
• CPC Class Codes: G01N 21/6454 using an integrated detector array
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence
• CPC Class Codes: G01N 2201/0627 Use of several LED's for spectral resolution

Abstract

A system for conducting a polymerase chain reaction (PCR) assay upon a collection of samples is disclosed. The PCR assay is performed by absorption detection. The system includes a multi-well plate which is adapted to retain a collection of sample wells. This system includes a thermal cycler for the multi-well plate. The system additionally includes a collection of photodetectors, and a corresponding number of light sources. The light sources are positioned such that light emitted from each of the respective light sources passes through a corresponding well retained in the multi-well plate and to a corresponding photodetector. The system also includes a processor or other means for analyzing the output signals from the photodetectors. In certain versions of the system, ultra-violet light is used.

Claims

1. A system for conducting a polymerase chain reaction assay upon a plurality of samples by absorbance detection, said system comprising:

a multi-well plate, said plate adapted to retain a plurality of sample wells;

a thermal cycler in thermal communication with said multi-well plate;

at least one photodetector, each said photodetector providing an output signal;

at least one light source,

said light source positioned such that light emitted therefrom passes through a corresponding well retained in said multi-well plate and to a corresponding photodetector of said plurality of photodetectors; and

a means for analyzing said output signals from said at least one photodetector and determining by absorbance detection information indicative of the polymerase chain reaction.

2. The system of claim 1 wherein said light source is selected from the group consisting of light emitting diodes, laser diodes, and combinations thereof.

3. The system of claim 1 wherein said light source emits light having a wavelength in the ultra-violet range.

4. The system of claim 1 wherein said system includes an array of light sources and an array of photodetectors configured to measure the absorbance or fluorescence signal from a plurality of wells, in parallel.

5. The system of claim 1, wherein said at least one light source includes a plurality of closely spaced light sources that sequentially emit light.

6. A system for conducting a polymerase chain reaction assay upon a plurality of samples, said system comprising:

a multi-well plate, said plate adapted to retain a plurality of sample wells;

a thermal cycler in thermal communication with said multi-well plate;

a plurality of photodetectors, each said photodetector providing an output signal;

at least one ultra-violet light source,

said at least one ultra-violet light source positioned such that light emitted therefrom passes through a corresponding well retained in said multi-well plate and to a corresponding photodetector of said plurality of photodetectors; and

a means for analyzing said out put signals from said plurality of photodetectors.

7. The system of claim 6 wherein said at least one ultra-violet light source includes a plurality of ultra-violet light emitting diodes.

8. The system of claim 6 wherein said at least one ultra-violet light source includes a plurality of lasers.

9. The system of claim 6 wherein said light emitted from said ultra-violet light source has a wavelength of from about 175 nm to about 350 nm.

10. The system of claim 9 wherein said wavelength is from about 240 to about 350 nm.

11. The system of claim 6 wherein said at least one ultra-violet light source emits light having a wavelength of 260 nm, 280 nm or a combination of 260 nm and 280 nm.

12. The system of claim 6 wherein said system provides real-time information indicative of the polymerase chain reaction.

13. A spectrophotometer for measuring the intensity of ultra-violet light, comprising:

a sample well adapted for retaining a liquid sample, said sample well defining a first region and a second region in fluid communication with said first region;

a photodetector;

a first ultra-violet light source positioned relative to said sample well and said photodetector such that ultra-violet light emitted from said first light source passes through said first region of said sample well to said photodetector; and

a second ultra-violet light source positioned relative to said sample well and said photodetector such that ultra-violet light emitted from said second light source passes through said second region of said sample well to said photodetector.

14. The spectrophotometer of claim 13 wherein said first and second ultra-violet light sources are light emitting diodes.

15. The spectrophotometer of claim 13 wherein said first and second ultra-violet light sources are lasers.

16. The spectrophotometer of claim 13 wherein said ultra-violet light sources emit light having a wavelength of from about 175 nm to about 350 nm.

17. The spectrophotometer of claim 16 wherein said wavelength is from about 240 nm to about 300 nm.

18. The spectrophotometer of claim 13 wherein said ultra-violet light source emits light having a wavelength of 260 nm, 280 nm, or a combination of 260 nm and 280 nm.

19. A method of performing a polymerase chain reaction assay by absorbance detection, said method comprising:

providing a system including (i) a multi-well plate adapted to retain a plurality of samples, (ii) a thermal cycler, (iii) a photodetector that provides an output signal, (iv) at least one light source positioned such that light emitted therefrom passes through said multi-well plate to said photodetector, and (v) a means for analyzing said output signal of said photodetector upon detecting light;

obtaining samples upon which said polymerase chain reaction assay is to be performed;

depositing said samples in said multi-well plate;

performing a polymerase chain reaction in said samples;

emitting light from said at least one light source such that said light passes through said samples and said multi-well plate to said photodetector; and

analyzing said output signal of said photodetector to determine the absorbance of light and information indicative of the polymerase chain reaction.

20. The method of claim 19 wherein said method is performed in real-time.

21. The method of claim 19 wherein said light source is selected from the group consisting of light emitting diodes, lasers, and combinations thereof.

22. The method of claim 19 wherein said light emitted from said light source has a wavelength of from about 100 nm to about 400 nm.

23. A method of performing a polymerase chain reaction assay, said method comprising:

providing a system including (i) a multi-well plate adapted to retain a plurality of samples, (ii) a thermal cycler, (iii) a photodetector that provides an output signal, (iv) a plurality of ultra-violet light sources positioned such that light emitted therefrom passes through said multi-well plate to said photodetector, and (v) a means for analyzing said output signal of said photodetector upon detecting ultra-violet light;

obtaining samples upon which said polymerase chain reaction assay is to be performed;

depositing said samples in said multi-well plate;

performing a polymerase chain reaction in said samples;

emitting ultra-violet light from said plurality of ultra-violet light sources such that said light passes through said samples to said photodetector; and

analyzing said output signal of said photodetector.

24. The method of claim 23 wherein said method is performed in real-time.

25. The method of claim 23 wherein said ultra-violet light has a wavelength of from about 175 nm to about 350 nm.

26. The method of claim 25 wherein said ultra-violet light has a wavelength of from about 240 nm to about 300 nm.

27. The method of claim 26 wherein said ultra-violet light has a wavelength of 260 nm, 280 nm, or a combination of 260 nm and 280 nm.