Method and apparatus to illuminate sample and containing vessel in a light scattering detector

• US 20130286381A1
• Filed: 04/26/2013
• Published: 10/31/2013
• Est. Priority Date: 04/27/2012
• Status: Active Grant

• Current Assignee: Wyatt Technology LLC (Waters Corporation)
• Original Assignee: Wyatt Technology Corporation
• Inventors: Some, Daniel I., Larkin, Michael I., Neilson, Peter G., Villalpando, David N.
• Granted Patent: US 8,964,177 B2
• Time in Patent Office: Days
• US Class Current: 356/72
• CPC Class Codes: G01N 21/51 inside a container, e.g. in an ampoule G01N21/53 takes precedence

Abstract

A method and apparatus for the illumination of a sample are disclosed. An imaging illumination light source is directed to pass through an absorbing/transmitting structure in order to illuminate the sample and any containing vessel. A diffuser may aid in properly dispersing the light from the imaging illumination source. A light sensitive detector such as a camera records an image therefrom. The beam from a light scattering source is directed through the sample and any containing vessel, and upon exiting the sample/vessel, impinges upon the absorbing/transmitting structure selected to absorb at the wavelength of the light scattering source. Scattered light from the sample is collected by a photo detector. Methods of use for the novel lighting system are also disclosed.

Claims

1. A method for recording an image of a liquid-borne sample previously prepared for light scattering measurement, said light scattering measurement made by transmitting a light beam of wavelength λ

₁ through said liquid-borne sample, where said light beam, after traversing said sample, intersects an absorbing/transmitting optical structure selected to absorb light selectively in a wavelength range spanning λ

₁, and some fraction of light scattered by said sample is allowed to fall upon a detector, where said image is recorded by the method comprising the steps of

A) providing illumination from one or more imaging illumination sources operating at a wavelength different from λ

₁ or at range of wavelengths, said imaging illumination passing through said absorbing/transmitting optical structure, said absorbing/transmitting optical structure is selected to permit the transmission of at least a portion of said imaging illumination, thereby illuminating said liquid-borne sample; and

B) recording an image produced of said liquid-borne sample.

2. The method of claim 1 where said image is recorded by optical camera means.

3. The method of claim 2 wherein said optical camera means comprises multiple cameras.

4. The method of claim 1 comprising the further step wherein said imaging illumination having traversed said absorbing/transmitting optical structure, is incident upon a diffusion means which reflects and/or scatters light, a portion of said reflected and/or scattered light is transmitted back through said absorbing/transmitting optical structure, thereby illuminating said liquid-borne sample.

5. The method of claim 4 where said diffusion means is a weatherproofed vinyl sheet.

6. The method of claim 1 comprising the further step of analyzing said recorded image to determine a relative likelihood of said measured scattered light being an accurate representation of the light scattered from sample alone.

7. The method of claim 1 where said liquid sample is held within a container.

8. The method of claim 7 where said container is a well of a microwell plate.

9. The method of claim 7 where said container is a cuvette.

10. The method of claim 1 wherein said light scattering measurement is a static light scattering measurement.

11. The method of claim 1 wherein said light scattering measurement is a dynamic light scattering measurement.

12. The method of claim 1 wherein said light scattering measurement is a phase analysis light scattering measurement.

13. The method of claim 1 comprising the further step of measuring fluorescence of said sample due to said imaging light source.

14. The method of claim 2 comprising the further step of displaying said recorded image on a computer monitor.

15. The method of claim 2 comprising the further step of storing a digital representation of said recorded image in a computer memory means.

16. The method of claim 15 comprising the further step of correlating said stored image with data corresponding to said light scattering measurement from the same liquid sample.

17. An apparatus for measuring light scattered from a liquid-borne sample and recording an image of said sample comprising

A) light scattering illumination source which transmits a beam of light of wavelength λ

₁ through said sample;

B) a detector oriented to detect light from said light scattering illumination source which is scattered by said sample;

C) an absorbing/transmitting optical structure positioned such that it intersects the path of said beam from said light scattering illumination source after traversing said sample,

D) imaging illumination means which generates light at a wavelength different from λ

₁ or at a range of wavelengths, positioned such that at least a portion of the light generated therefrom is transmitted through said absorbing/transmitting optical structure; and

E) imaging means positioned to record an image of said sample,

where said absorbing/transmitting optical structure is selected so as to both absorb light selectively in a wavelength range spanning λ

₁, and to permit the transmission of at least a portion of said light generated by said imaging illumination means.

18. The apparatus of claim 17 further comprising a diffusion means positioned such that a fraction of the light from said imaging illumination means, after passing through said absorbing/transmitting optical structure is reflected and/or scattered therefrom and a portion of said reflected and/or scattered illumination is transmitted back through said absorbing/transmitting optical structure, thereby illuminating said liquid-borne sample.

19. The apparatus of claim 18 wherein said diffusion means is a weatherproofed vinyl sheet.

20. The apparatus of claim 17 wherein said absorbing/transmitting optical structure is a glass plate which absorbs light at or near the wavelength of said light scattering source, λ

₁.

21. The apparatus of claim 17 wherein said light scattering illumination source is a laser.

22. The apparatus of claim 21 wherein λ

₁ is 830 nm.

23. The apparatus of claim 17 wherein said absorbing/transmitting optical structure allows transmission of light at 530 nm.

24. The apparatus of claim 17 wherein said imaging illumination means comprises one or more light emitting diodes.

25. The apparatus of claim 17 wherein said imaging illumination means comprises a plurality of imaging illumination sources.

26. The apparatus of claim 27 wherein said multiple imaging illumination sources produce diffuse light.

27. The apparatus of claim 17 wherein said imaging means comprises one or more optical cameras.

28. The apparatus of claim 17 further comprising a Peltier heater/cooler unit in contact with said absorbing/transmitting optical structure, said Peltier heater/cooler is capable of dissipating heat within said absorbing/transmitting optical structure generated by absorption of said light scattering illumination source beam.

29. The apparatus of claim 17 wherein said imaging illumination means is located on the same side of said absorbing/transmitting optical structure as said light scattering illumination source.

30. The apparatus of claim 17 wherein said absorbing/transmitting optical structure is located between said imaging illumination source and said sample.

31. The apparatus of claim 17 wherein said absorbing/transmitting optical structure is coated such that light from said imaging illumination source transmitted there through is reflected by said coating.

32. The apparatus of claim 20 wherein one surface of said glass plate is at least partially coated with an anti-reflection layer.