SYSTEMS AND METHODS FOR MONITORING THE AMPLIFICATION AND DISSOCIATION BEHAVIOR OF DNA MOLECULES

• US 20080130971A1
• Filed: 11/29/2007
• Published: 06/05/2008
• Est. Priority Date: 11/30/2006
• Status: Active Grant

• Current Assignee: Canon USA, Inc. (Canon Inc.)
• Original Assignee: Canon USA, Inc. (Canon Inc.)
• Inventors: Keady, John P., Hasson, Kenton C., Dale, Gregory A.
• Granted Patent: US 7,593,560 B2
• Time in Patent Office: Days
• US Class Current: 382/129
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: C12Q 1/686 Polymerase chain reaction [PCR]
• 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 21/6456 Spatial resolved fluorescence measurements; Imaging
• CPC Class Codes: H01L 27/146 Imager structures

Abstract

The present invention relates to systems and methods for monitoring the amplification of DNA molecules and the dissociation behavior of the DNA molecules.

Claims

1. In an environment comprising (i) a chip comprising a microchannel and (ii) an image sensor having a pixel array, wherein at least a portion of the microchannel is within a field of view of the pixel array, a nucleic acid analysis method comprising:

introducing a sample of a solution comprising nucleic acid into the microchannel;

forcing the sample to move though the channel;

defining a first window of the pixel array;

defining a second window of the pixel array, wherein the center of the second window is spaced apart from the center of the first window; and

while the sample is moving through the microchannel, performing the steps of;

(a) exposing the first window of the pixel array to light emitted from the sample at a time when the sample is within a field of view of first window and then selectively outputting first image data from the pixel array, wherein the step of selectively outputting the first image data from the pixel array comprises outputting data from only the first window of the pixel array; and

(b) after performing step (a), exposing the second window of the pixel array to light emitted from the sample at a time when the sample is within a field of view of the second window and then selectively outputting second image data from the pixel array, wherein the step of selectively outputting the second image data from the pixel array comprises outputting data from only the second window of the pixel array.

2. The method of claim 1, wherein, when the step of exposing the first window of the pixel array to light emitted from the sample is performed, the center of the first window corresponds substantially to the center of the sample.

3. The method of claim 2, wherein, when the step of exposing the second window of the pixel array to light emitted from the sample is performed, the center of the second window corresponds substantially to the center of the sample.

4. The method of claim 1, wherein the size of the second window is less than the size of the first window.

5. The method of claim 4, wherein the step of defining the second window occurs after step (a).

6. The method of claim of claim 5, wherein the step of defining the second window comprises processing the first image data to determine whether the amount of light received at a pixel located at the edge of the first window exceeds or equals a predetermined threshold.

7. The method of claim 1, further comprising the step of receiving from a sensor a signal indicating that the sample has been detected by the sensor.

8. The method of claim 7, further comprising the step of receiving from a second sensor a second signal indicating that the sample has been detected by the second sensor, wherein the first sensor is positioned to detect when the sample enters the field of view of the image sensor and the second sensor is positioned to detect when the sample leaves the field of view of the image sensor.

9. The method of claim 1, wherein the step of defining the first window of the pixel array comprises determining the size of the window, wherein the determination is based, at least in part, on the length of the sample.

10. The method of claim 1, wherein the step of defining the first window of the pixel array comprises determining the size of the window, wherein the determination is based, at least in part, on the length of the sample, and the step of defining the second window of the pixel array comprises determining the location of the center of the second window, wherein the determination is based, at least in part, on a speed at which the sample moves through the channel.

21. The method of claim 1, further comprising:

receiving from a first sensor a signal indicating that the sample has been detected by the sensor; and

receiving from a second sensor a second signal indicating that the sample has been detected by the second sensor, wherein

the first sensor is positioned to detect when the sample enters the field of view of the image sensor; and

the second sensor is positioned to detect when the sample leaves the field of view of the image sensor.

22. The method of claim 1, wherein the step of defining the first window of the pixel array comprises determining the size of the window, wherein the determination is based, at least in part, on the length of the sample, and the step of defining the second window of the pixel array comprises determining the location of the center of the second window, wherein the determination is based, at least in part, on a speed at which the sample moves through the channel.

11. A DNA analysis system, comprising:

a chip comprising a microchannel for receiving a sample of solution comprising nucleic acid and for providing a path for the sample to traverse;

an image sensor having a pixel array, wherein at least a portion of the microchannel is within a field of view of the pixel array; and

an image sensor controller configured to;

(a) read only a first window of the pixel array at time when the sample is within a field of view of the first window, thereby producing first image data, and (b) read only a second window of the pixel array at time when the sample is within a field of view of the second window, wherein

the center of the second window is spaced apart from the center of the first window.

12. The system of claim 11, wherein the image sensor controller is configured to use the first data to determine the size of the second window and the size of the second window is less than the size of the first window.

13. The system of claim of claim 11, wherein the image sensor controller is configured to process the first image data to determine whether the amount of light received at a pixel located at an edge of the first window exceeds or equals a predetermined threshold.

14. The system of claim 11, further comprising a first sample sensor positioned to detect the sample when the sample enters or is about to enter the field of view of the image sensor and configured to output a signal in response to detecting the sample.

15. The system of claim 14, further comprising a second sample sensor positioned to detect the sample when the sample leaves or is about to leave the field of view of the image sensor and configured to output a signal in response to detecting the sample.

16. The system of claim 11, wherein the image sensor controller is configured to determine a size for the first window, wherein the determination is based, at least in part, on the length of the sample, and the image sensor controller is configured to determine a location of the center of the second window, wherein the determination is based, at least in part, on a speed at which the sample moves through the channel.

17. A DNA analysis method comprising:

introducing a sample of a solution comprising nucleic acid into a microchannel;

causing the sample to move though the channel;

defining a first window of a pixel array of an image sensor;

defining a second window of the pixel array, wherein the center of the second window is spaced apart from the center of the first window;

while the sample is moving through the microchannel, performing the steps of;

(a) windowing the image sensor so that image data from the first window is output to a data buffer, wherein said image data comprises data from which the intensity of emissions from the sample can be determined; and

(b) after performing step (a), windowing the image sensor so that image data from the second window is output to a data buffer, wherein said image data comprises data from which the intensity of emissions from the sample can be determined.

18. The method of claim 17, wherein the size of the second window is less than the size of the first window.

19. The method of claim 17, wherein the step of defining the second window occurs after step (a).

20. The method of claim of claim 19, wherein the step of defining the second window comprises processing the image data from the first window to determine whether the amount of light received at a pixel located at an edge of the first window exceeds or equals a predetermined threshold.

23. A DNA analysis method comprising:

introducing a first sample of a solution comprising nucleic acid into a first microchannel;

introducing a second sample of a solution comprising nucleic acid into a second microchannel;

causing the first sample to move though the first channel;

causing the second sample to move though the second channel;

defining a first window of a pixel array of an image sensor, wherein at least a portion of the first channel is within the field of view of the first window;

defining a second window of the pixel array, wherein at least a portion of the second channel is within the field of view of the second window and wherein the center of the second window is spaced apart from the center of the first window;

while the samples are moving through the respective microchannels, performing the steps of;

(a) windowing the image sensor so that image data from the first window is output to a data buffer, wherein said image data comprises data from which the intensity of emissions from the first sample can be determined; and

(b) after performing step (a), windowing the image sensor so that image data from the second window is output to a data buffer, wherein said image data comprises data from which the intensity of emissions from the second sample can be determined.

25. The method of claim 23, wherein the step of defining the first window of the pixel array comprises determining the size of the window, wherein the determination is based, at least in part, on the length of the sample.

24. The method of claim 32, wherein the first window and the second window do not overlap.