Excitation and emission filter

1. A fluorescent detection system comprising:

an array of excitation light sources positioned to correspond to an array of sample chambers, wherein at least two excitation light sources in the array emit a different wavelength range of light to each sample chamber in the array of sample chambers;

an array of detectors positioned to correspond to the array of sample chambers; and

a filter assembly comprising an excitation filter positioned for excitation light from the excitation light sources and an emission filter positioned for fluorescent light from the array of samples, wherein the excitation filter and emission filter are positioned substantially parallel to each other.

2. The fluorescent detection system of claim 1 , wherein the two excitation light sources are narrow band sources and the one detector is a broad band detector.

3. The fluorescent detection system of claim 2 , wherein the excitation filter substantially rejects wavelengths outside those of the narrow band sources.

4. The fluorescent detection system of claim 3 , wherein the emission filter substantially rejects wavelengths of the narrow band sources.

5. The analytical instrument of claim 4 , wherein the excitation filter has a maximum wavelength of at most 535 nm and the excitation filter exhibits at least 80% efficiency in rejecting wavelengths greater than the maximum wavelength.

6. The analytical instrument of claim 5 , wherein the emission filter has a minimum wavelength of at least 535 nm and the excitation filter exhibits at least about 80% efficiency in rejecting wavelengths less than the minimum wavelength.

7. The analytical instrument of claim 6 , wherein the maximum wavelength is 10 nm or more shorter than the minimum wavelength.

8. The fluorescent detection system of claim 1 , further comprising an array of focusing lenses.

9. The fluorescent detection system of claim 8 , wherein each focusing lens corresponds to each sample.

10. The fluorescent detection system of claim 8 , wherein a first set of focusing lenses corresponds to the excitation light and a second set of the focusing lenses corresponds to the fluorescent light.

11. The fluorescent detection system of claim 1 , further comprising an array of collimating lenses.

12. The fluorescent detection system of claim 11 , wherein the array of collimating lenses comprises a first set of collimating lenses for the excitation light and a second set of collimating lenses for the fluorescent light.

13. The fluorescent detection system of claim 1 ;

wherein the excitation filter and the emission filter form alternating portions of the filter assembly, wherein the filter assembly is substantially flat.

14. The filter assembly of claim 13 , wherein the excitation filter and emission filter are separate structures coupled together.

15. The filter assembly of claim 14 , wherein the excitation filter and the emission filter form a lattice with nodes and openings.

16. The filter assembly of claim 15 , wherein the nodes and openings are positioned in a staggered array.

17. The filter assembly of claim 13 , wherein the excitation filter and the emission filter are part of one substrate.

18. The filter assembly of claim 17 , wherein the excitation filter comprises a coating on the substrate.

19. The filter assembly of claim 17 , wherein the emission filter comprises a coating on the substrate.

20. The filter assembly of claim 17 , wherein the substrate comprises a first layer configured to provide the excitation filter and a second layer configured to provide the emission filter.

21. The fluorescent detection system of claim 1 , wherein the excitation filter and emission filter are positioned substantially parallel to each other in different parallel planes.

22. The fluorescent detection system of claim 1 , wherein the excitation filter and emission filter are positioned substantially parallel to each other in the same plane.

23. A method of fluorescent detection comprising:

providing a filter assembly comprising:

an excitation filter, and

an emission filter; wherein the excitation filter and emission filter are positioned substantially parallel to each other;

providing an array of excitation light sources positioned to correspond to an array of sample chambers, wherein at least two excitation light sources in the array emit a different wavelength range of light to each sample chamber in the array of sample chambers;

positioning the excitation light sources to correspond with the excitation filter;

conditioning the excitation light with the excitation filter;

providing a sample in a sample chamber adapted to generate fluorescent light when excited by the excitation light of two or more wavelengths;

positioning the fluorescent light to correspond with the emission filter;

conditioning the fluorescent light with the emission filter;

detecting the conditioned fluorescent light to determine the presence of two or more components in the sample.

24. The method of claim 23 , wherein conditioning the excitation light comprises substantially rejecting wavelengths in a wavelength range of the fluorescent light.

25. The method of claim 23 , wherein conditioning the emission light comprises substantially rejecting wavelengths in a wavelength range of the excitation light.

26. The method of claim 23 , wherein positioning the excitation light comprises aligning an array of the samples with an array of excitation light sources.

27. The method of claim 23 , wherein positioning the fluorescent light comprises aligning an array of the samples with an array of detectors.

28. The method of claim 23 , wherein the components in the sample are nucleic acid sequences.