High performance fluorescence imaging module for genomic testing assay
Fluorescence imaging system designs are described that provide larger fields-of-view, increased spatial resolution, improved modulation transfer and image quality, higher spatial sampling frequency, faster transitions between image capture when repositioning the sample plane to capture a series of images (e.g., of different fields-of-view), and improved imaging system duty cycle, and thus enable higher throughput image acquisition and analysis for genomics and other imaging applications.
1. A method for nucleic acid sequencing, said method comprising:
a) providing a flow cell comprising (i) a first surface comprising a first plurality of primed nucleic acid sequences coupled thereto and (ii) a second surface comprising a second plurality of primed nucleic acid sequences coupled thereto, wherein said second surface is axially displaced from said first surface along an optical path;
b) contacting said first plurality of primed nucleic acid sequences and said second plurality of primed nucleic acid sequences with (i) a plurality of nucleotide moieties comprising a plurality of fluorescent labels, and (ii) a polymerizing enzyme under conditions such that at least a subset of said plurality of nucleotide moieties couple to at least a subset of said first plurality of primed nucleic acid sequences and said second plurality of primed nucleic acid sequences; and
c) imaging said first surface and said second surface to detect a plurality of signals from a subset of said plurality of fluorescent labels, wherein said detecting comprises:
(i) illuminating said first surface and said second surface with a first light provided by a structured illumination system under a first set of illumination conditions to project a first plurality of fringes oriented in a specific direction on said first surface and said second surface;
(ii) capturing a first plurality of phase images of said first surface and said second surface;
(iii) illuminating said first surface and said second surface with a second light provided by said structured illumination system under a second set of illumination conditions to project a second plurality of fringes on said first surface and said second surface; and
(iv) capturing a second plurality of phase images of said first surface and said second surface illuminated with said second plurality of fringes.
2. The method of claim 1 , wherein:
(i) during said capturing of said first plurality of phase images in (c)(ii), positions of said first plurality of fringes are shifted on said first surface and said second surface;
(ii) said second plurality of fringes are angularly offset from said first plurality of fringes on said first surface and said second surface; and
(iii) during said capturing of said second plurality of phase images, positions of said second plurality of fringes are shifted on said first surface and said second surface.
3. The method of claim 1 , wherein a nucleotide moiety of said plurality of nucleotide moieties is conjugated to a polymer core to form a conjugated polymer-nucleotide.
4. The method of claim 3 , wherein said contacting in (b) comprises contacting said first plurality of primed nucleic acid sequences and said second plurality of primed nucleic acid sequences with said conjugated polymer-nucleotide to form a transient binding complex between at least one primed nucleic acid sequence of said first plurality of primed nucleic acid sequences and said second plurality of primed nucleic acid sequences, and a nucleotide moiety of said conjugated polymer-nucleotide, when said nucleotide moiety is complementary to a nucleotide of said at least one primed nucleic acid sequence.
5. The method of claim 4 , wherein said imaging in (c) comprises detecting a plurality of signals from said transient binding complex.
6. The method of claim 1 , wherein said first plurality of fringes and said second plurality of fringes are generated by a diffraction grating.
7. The method of claim 1 , wherein said structured illumination system comprises a light source.
8. The method of claim 6 , wherein said diffraction grating comprises a horizontal grating, vertical grating, or any combination thereof.
9. The method of claim 8 , wherein said first surface is illuminated by said vertical grating and said second surface is illuminated by said horizontal grating.
10. The method of claim 6 , wherein said diffraction grating comprises a transmissive phase diffraction grating.
11. The method of claim 1 , wherein said second plurality of fringes is shifted by about 90 degrees from said first plurality of fringes.
12. The method of claim 1 , wherein said structured illumination system comprises an optical phase modulator or phase shifter.
13. The method of claim 12 , wherein said optical phase modulator or said phase shifter shifts said first plurality of fringes and second plurality of fringes by ½, ⅓, or ¼ of a pitch of said first plurality of fringes and said second plurality of fringes.
14. The method of claim 12 , wherein said optical phase modulator comprises rotating optical phase plates actuated by rotatory actuators.
15. The method of claim 1 , wherein said structured illumination system comprises one or more of:
(1) a collimating optical element;
(2) a polarizer; and
(3) a diffraction grating.
16. The method of claim 1 , wherein said structured illumination system comprises a partially-silvered mirror that combines said first light and said second light.
17. The method of claim 1 , wherein said first plurality of phase images or said second plurality of phase images comprise at least 1 angular orientation of said first plurality of fringes or said second plurality of fringes.
18. The method of claim 1 , wherein said first plurality of phase images or said second plurality of phase images further comprise at least 1 phase shift of said first plurality of fringes or said second plurality of fringes.
19. The method of claim 1 , wherein a nucleotide moiety of said at least said subset of said plurality of nucleotide moieties couples to a primed nucleic acid sequence of said at least said subset of said first plurality of primed nucleic acid sequences and said second plurality of primed nucleic acid sequences in (b) by incorporating said nucleotide moiety into said primed nucleic acid.
20. The method of claim 1 , wherein:
(a) said structured illumination system comprises:
(i) a light source;
(ii) an optical phase modulator that rotates optical phase plates actuated by rotatory actuator;
(iii) a phase shifter that shifts said first plurality of fringes and said second plurality of fringes by ½, ⅓, or ¼ of a pitch of said first plurality of fringes and said second plurality of fringes;
(iv) a collimating optical element;
(v) a polarizer;
(vi) a diffraction grating that generates said first plurality of fringes and second plurality of fringes, wherein said diffraction grating comprises a horizontal grating, vertical grating, a transmissive phase diffraction grating, or any combination thereof, and wherein said second plurality of fringes is shifted by about 90 degrees from said first plurality of fringes; and
(vii) a partially-silvered mirror that combines said first light and said second light; and
(b) said first plurality of phase images or said second plurality of phase images comprises:
(viii) at least 1 angular orientation of said first plurality of fringes or said second plurality of fringes; and
(ix) at least 1 phase shift of said first plurality of fringes or said second plurality of fringes.