System for Performing Scattering and Absorbance Assays

• US 20120120388A1
• Filed: 10/17/2011
• Published: 05/17/2012
• Est. Priority Date: 10/29/2010
• Status: Active Grant

• Current Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Harbers, Rik
• Granted Patent: US 9,285,311 B2
• Time in Patent Office: Days
• US Class Current: 356/73
• CPC Class Codes: G01N 21/51 inside a container, e.g. in an ampoule G01N21/53 takes precedence
• CPC Class Codes: G01N 21/59 Transmissivity G01N21/25 takes precedence

Abstract

An optical system for performing scattering and absorbance assays in clinical diagnostics comprises a light source for emitting collimated light parallel to an optical axis in an optical path, a sample holding unit comprising at least one sample holding position located in the optical path and an optical detector for measuring light transmitted through a sample located in a sample holding position. The optical system further comprises an adjustable light angle selector adjusted to prevent light transmitted through the sample and diverging from the optical axis with an angle greater than a certain value from reaching the detector when a scattering assay is performed, and wherein the light angle selector is adjusted to allow light transmitted through the sample and diverging from the optical axis with an angle smaller than a certain value to reach the detector when an absorbance assay is performed.

Claims

1. An optical system for performing scattering and absorbance assays in clinical diagnostics, the optical system comprising:

a light source for emitting collimated light parallel to an optical axis in an optical path,

a sample holding unit comprising at least one sample holding position,

an optical detector for measuring light transmitted through a sample being located in the optical path in the sample holding position, and

an adjustable light angle selector comprising at least one of the following;

at least one lens with a focal length (f) and a diaphragm with variable aperture or an LCD with switchable pixels, located at the focal length (f),

a group of lenses and a driver for varying the relative distance between lenses as a zoom objective with variable focal length (f), and

a driver for varying the relative distance between the sample holding position and the detector along the optical axis, wherein

for a scattering assay, said light angle selector is adapted to be adjusted such as to allow only light transmitted through the sample and diverging from the optical axis with an angle (α

) less than about 5 degrees to reach the detector, and

for an absorbance assay, said light angle selector is adapted to be adjusted such as to allow light transmitted through the sample and diverging from the optical axis with an angle (α

) less than about 60 degrees to reach the detector.

2. The optical system according to claim 1, wherein for a scattering assay the light angle selector is adapted to be adjusted such as to allow only light transmitted through the sample and diverging from the optical axis with an angle (α

) of about 3 degrees or less to reach the detector.

3. The optical system according to claim 1, wherein the diaphragm is configured to vary the aperture according to the assay type and the desired sensitivity to scattering, the smaller the aperture the higher the sensitivity to scattering.

4. The optical system according to claim 1, wherein each pixel of the LCD is configured to be switched off such as to block light or to be switched on such as to allow light to pass through according to the assay type and the desired sensitivity to scattering, the smaller the number of pixels in the center allowing light to reach the detector the higher the sensitivity to scattering.

5. The optical system according to claim 1, wherein the objective is configured to vary the focal length (f) according to the assay type and the desired sensitivity to scattering, the longer the focal length (f) the higher the sensitivity to scattering.

6. The optical system according to claim 1, wherein the driver is configured to vary the distance between the sample holding position and the detector according to the assay type and the desired sensitivity to scattering, the larger the distance the higher the sensitivity to scattering.

7. The optical system according to claim 1 further comprising a control unit for automatically adjusting the light angle selector according to the assay type and/or particular assay parameters to be determined.

14. An instrument for performing scattering and absorbance assays in clinical diagnostics, the instrument comprising:

the optical system according to claim 1,

a sample holding unit for receiving samples to be assayed,

a reagent holding unit for holding reagents to perform the assays,

a cuvette feeding unit for feeding optical cuvettes to the sample holding unit, and

a liquid processing unit to deliver samples and/or reagents to optical cuvettes.

8. A method for performing scattering and absorbance assays in clinical diagnostics, the method comprising the steps of:

emitting collimated light from a light source parallel to an optical axis in an optical path,

measuring light with a detector transmitted through a sample being located in the optical path in a sample holding unit,

adjusting a light angle selector such as to allow only light transmitted through the sample and diverging from the optical axis with an angle (α

) less than about 5 degrees to reach the detector when a scattering assay is being performed, or

adjusting said light angle selector such as to allow light transmitted through the sample and diverging from the optical axis with an angle (α

) less than about 60 degrees to reach the detector when an absorbance assay is being performed.

9. The method according to claim 8 further comprising the step of automatically adjusting the light angle selector according to the assay type and/or particular assay parameters to be determined.

10. The method according to claim 8, wherein adjusting the light angle selector comprises the step of varying the aperture of a diaphragm according to the assay type and the desired sensitivity to scattering, the smaller the aperture the higher the sensitivity to scattering, or the step of varying the number of pixels of an LCD, which allow light to reach the detector, according to the assay type and the desired sensitivity to scattering, the smaller the number of pixels allowing light to reach the detector the higher the sensitivity to scattering.

11. The method according to claim 8, wherein adjusting the light angle selector comprises the step of varying the relative distance between lenses such as to vary focal length (f) according to the assay type and the desired sensitivity to scattering, the longer the focal length (f) the higher the sensitivity to scattering.

12. The method according to claim 8, wherein adjusting the light angle selector comprises the step of varying the relative distance between the sample holding position and the detector according to the assay type and the desired sensitivity to scattering, the larger the distance the higher the sensitivity to scattering.

13. The method according to claim 8 further comprising the step of automatically determining an assay sequence based on the assay type and/or particular assay parameters to be determined.