Optical adapter with a card slot for imaging a thin sample layer
Disclosed are devices and methods for analyzing an analyte, such as white blood cells in liquid samples.
1. An adapter device for analyzing an analyte in a liquid sample, comprising:
(a) an attachment member configured to attach the adapter device to an apparatus that comprises a light source and a camera;
(b) a card slot configured to accommodate a sample card, which contains a liquid sample that is compressed into a layer of uniform thickness, wherein when the sample card inserted into the card slot, the sample is positioned under the view of the camera and the light source;
(c) the light source forms a first beam with a specific wavelength range, wherein a part of the first beam illuminates on the edge of the sample card and travels in the sample card to illuminate the sample;
(d) a mirror configured to deflect part of the first beam to form a second beam that back-illuminates the sample in an oblique angle; and
(e) an absorber configured to absorb at least a part of the first beam that is not deflected by the mirror.
2. The device of claim 1 , wherein the adapter comprises a bandpass excitation filter with a transmission band from 450 nm to 480 nm.
3. The device of claim 1 , wherein the adapter device comprises a long pass emission filter with cut-on wavelength between 510 nm and 525 nm.
4. The device of claim 1 , wherein the adapter device comprises an excitation light illumination with an oblique angle larger than the collection angle of the camera of the apparatus which the adapter device attaches to.
5. The device of claim 1 , wherein the adapter device comprises a lens including a focus distance between 2 mm and 6 mm that enables the camera to image the sample inserted into the adapter device.
6. The device of claim 1 , wherein the adapter device comprises a bandpass filter with transmission band from 520 nm to 580 nm.
7. The device of claim 1 , wherein the adapter device comprises a light illumination angle 85 degree to 95 degree relative to the surface of the sample.
8. The device of claim 1 , wherein the adapter device comprises a lens including a focus distance between 2 mm and 4 mm that enables the camera to image the sample inserted into the adapter device.
9. The device of claim 1 , wherein the average thickness of the layer of uniform thickness is in the range of 2.0 um to 7.5 um.
10. The device of claim 1 , wherein the average thickness of the layer of uniform thickness is in the range of 7.5 um to 10.5 um.
11. The device of claim 1 , wherein the average thickness of the layer of uniform thickness is in the range of 9.5 um to 12.5 um.
12. The device of claim 1 , wherein the average thickness of the layer of uniform thickness is in the range of 9.5 um to 12.5 um.
13. The device of claim 1 , wherein the average thickness of the layer of uniform thickness is in the range of 11.5 um to 13.5 um.
14. The device of claim 1 , wherein the average thickness of the layer of uniform thickness is in the range of 12.5 um to 14.5 um.
15. The device of claim 1 , wherein the average thickness of the layer of uniform thickness is in the range of 13.5 um to 16 um.
16. A method for analyzing an analyte in a liquid sample, comprising:
(a) obtaining the liquid sample;
(b) compressing at least part of the sample into a layer of uniform thickness with a sample card,
(c) inserting the sample card into an adaptor device, which is configured to be attached to an apparatus that comprises a light source and a camera;
(d) illuminating the sample with light from the light source, wherein
i. the light forms a first beam with a specific wavelength range, part of the first beam illuminating on the edge of the sample card and travels in the sample card to illuminate the sample;
ii. part of the first beam is deflected by a mirror of the adapter device to form a second beam that back-illuminates the sample in an oblique angle; and
iii. at least a part of the first beam that is not deflected by the mirror is absorbed by an absorber of the adapter device.
17. The method of claim 16 , wherein the adapter device comprises a bandpass excitation filter with a transmission band from 450 nm to 480 nm.
18. The method of claim 16 , wherein the adapter device comprises a long pass emission filter with cut-on wavelength between 510 nm and 525 nm.
19. The device of claim 16 , wherein the adapter device comprises an excitation light illumination with an oblique angle larger than the collection angle of the camera of the apparatus which the adapter device attaches to.
20. The method of claim 16 , wherein the adapter device comprises a lens including a focus distance between 2 mm and 6 mm.
21. The method of claim 16 , wherein the adapter device comprises a bandpass filter with transmission band from 520 nm to 580 nm.
22. The method of claim 16 , wherein the adapter device comprises a light illumination angle 85 degree to 95 degree relative to the surface of the sample.
23. The method of claim 16 , wherein the adapter device comprises a lens including a focus distance between 2 mm and 4 mm.
24. The method of claim 16 , wherein the average thickness of the layer of uniform thickness is in the range of 2.0 um to 7.5 um.
25. The method of claim 16 , wherein the average thickness of the layer of uniform thickness is in the range of 7.5 um to 10.5 um.
26. The method of claim 16 , wherein the average thickness of the layer of uniform thickness is in the range of 9.5 um to 12.5 um.
27. The method of claim 16 , wherein the average thickness of the layer of uniform thickness is in the range of 9.5 um to 12.5 um.
28. The method of claim 16 , wherein the average thickness of the layer of uniform thickness is in the range of 11.5 um to 13.5 um.
29. The method of claim 16 , wherein the average thickness of the layer of uniform thickness is in the range of 12.5 um to 14.5 um.
30. The method of claim 16 , wherein the average thickness of the layer of uniform thickness is in the range of 13.5 um to 16 um.