Scanning fluorometer

• US 6,313,471 B1
• Filed: 03/23/1999
• Issued: 11/06/2001
• Est. Priority Date: 08/18/1998
• Status: Expired due to Fees

• Current Assignee: Molecular Devices
• Original Assignee: Molecular Devices
• Inventors: Kaye, Roger, Ogle, David G., Giebeler, Robert
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Gabor, Otilia
• Application Number:
  US09/274,791
• Time in Patent Office: 959 Days
• Field of Search: 250/458.1, 250/461.1, 250/461.2, 250/459.1
• US Class Current: 250/458.1
• CPC Class Codes: G01N 2021/6471 Special filters, filter wheel
• CPC Class Codes: G01N 2021/6484 Optical fibres
• CPC Class Codes: G01N 21/6452 Individual samples arranged in a regular 2D-array, e.g. multiwell plates

Abstract

A method and apparatus for determining the fluorescence, luminescence, or absorption of a sample is provided. The sample may either be contained within a cuvette or within one or more sample wells within a multi-assay plate. A combination of a broadband source, a monochromator, and a series of optical filters are used to tune the excitation wavelength to a predetermined value within a relatively wide wavelength band. A similar optical configuration is used to tune the detection wavelength. In one aspect, multiple optical fibers are coupled to the excitation source subassembly, thus allowing the system to be quickly converted from one optical configuration to another. In another aspect, the excitation light and the detected sample emissions pass to and from an optical head assembly via a pair of optical fibers. The optical head assembly is scanned across one axis of the sample multi-assy plate. The multi-assay plate is mounted to a carriage assembly that scans the plate along a second axis orthogonal to the first axis.

Claims

1. A sample characterizing instrument, comprising:

a source of excitation light comprising;

a lamp;

a scanning monochromator; and

a plurality of optical filters within a filter wheel;

a sample testing region;

a detection assembly comprising;

a detector;

a second scanning monochromator; and

a second plurality of optical filters within a second filter wheel;

an optical assembly coupled to said excitation light source and coupled to said detection assembly, wherein said optical assembly directs said excitation light to said sample testing region, and wherein said optical assembly directs sample light from said sample testing region to said detection assembly;

a heater coupled to said sample testing region;

a temperature monitor coupled to said sample testing region;

an air circulation system, said air circulation system circulating air within said sample testing region;

a processor coupled to said heater and said temperature monitor, wherein said processor maintains a temperature with a predetermined temperature variation proximate to said sample testing region, and wherein said processor maintains a humidity proximate to said sample testing region in excess of 90 percent;

a distance sensing assembly coupled to said processor, said distance sensing assembly determining a distance between an upper surface of said sample testing region and a lid surface in said sample testing region; and

a carriage assembly coupled to said processor, wherein said carriage assembly controls said distance between said upper surface of said sample testing region and said lid surface.

2. A sample characterizing instrument, comprising:

a source of excitation light;

a detection assembly;

a first sample testing region, wherein said first sample testing region corresponds to a multi-assay plate testing region;

an optical head assembly coupled to said excitation light source and coupled to said detection assembly, wherein said optical head assembly directs said excitation light to said first sample testing region, and wherein said optical head assembly directs sample light from said first sample testing region to said detection assembly;

an optical fiber shutter assembly, wherein said optical fiber shutter assembly controls which of a plurality of optical fibers is coupled to said detection assembly;

a first optical fiber of said plurality of optical fibers, said first optical fiber coupling said optical head assembly to said detection assembly, wherein said excitation light source irradiates a first side of said first sample testing region and said first optical fiber receives sample light from said first side of said first sample testing region; and

a second optical fiber of said plurality of optical fibers, said second optical fiber coupling said detection assembly to a second side of said first sample testing region.

3. The sample characterizing instrument of claim 2, said source of excitation light firther comprising a lamp, a scanning monochromator, and a plurality of optical filters within a filter wheel.

4. The sample characterizing instrument of claim 2, said detection assembly further comprising a detector, a scanning monochromator, and a plurality of optical filters within a filter wheel.

5. The sample characterizing instrument of claim 2, further comprising a processor coupled to said excitation light source and to said detection assembly, wherein said processor controls an output wavelength, a lamp frequency, and an output duration corresponding to said excitation light source, and wherein said processor controls a detection wavelength of said detection assembly.

6. The sample characterizing instrument of claim 2, further comprising a carriage assembly coupled to said optical head assembly, wherein said carriage assembly scans said optical head assembly along at least one axis.

7. The sample characterizing instrument of claim 2, further comprising a carriage assembly coupled to said first sample testing region, wherein said carriage assembly scans said first sample testing region along at least one axis.

10. The sample characterizing instrument of claim 2, wherein said sample characterizing instrument characterizes a material property selected from the group consisting of fluorescence, luminescence, and absorption.

11. The sample characterizing instrument of claim 2, further comprising:

a second optical fiber shutter assembly, wherein said second optical fiber shutter assembly controls which of a second plurality of optical fibers is coupled to said excitation light source;

a first optical fiber of said second plurality of optical fibers coupling said optical head assembly to said excitation light source, wherein said first optical fiber of said second plurality of optical fibers causes said excitation light source to irradiate said first side of said first sample testing region; and

a second optical fiber of second said plurality of optical fibers coupling said optical head assembly to said excitation light source, wherein said second optical fiber of said second plurality of optical fibers causes said excitation light source to irradiate said second side of said first sample testing region.

8. The sample characterizing instrument of sample 2, further comprising a second sample testing region, wherein said second sample testing region corresponds to a cuvette cell testing region, said cuvette cell testing region coupled to said excitation source, wherein a third optical fiber of said plurality of optical fibers couples said detection assembly to said second sample testing region.

9. The sample characterizing instrument of claim 8, further comprising:

a second optical fiber shutter assembly, wherein said second optical fiber shutter assembly controls which of a second plurality of optical fibers is coupled to said excitation light source;

a first optical fiber of said second plurality of optical fibers coupling said optical head assembly to said excitation light source, wherein said first optical fiber of said second plurality of optical fibers causes said excitation light source to irradiate said first side of said first sample testing region; and

a second optical fiber of second said plurality of optical fibers coupling said excitation light source to said second sample testing region.

12. A sample characterizing instrument, comprising:

a source of excitation light comprising a lamp, a scanning monochromator, and a plurality of optical filters within a filter wheel;

a processor coupled to said excitation light source, said processor controlling an output wavelength, a lamp frequency, and an output duration corresponding to said excitation light source;

a sample holding tray for holding a multi-well multi-assay plate, said sample holding tray coupled to a first carriage assembly, said first carriage assembly providing translation of said sample holding tray along a first axis from a sample testing region to a sample holding region, said first carriage assembly providing translation of said multi-well multi-assay plate along said first axis within said sample testing region, said first carriage assembly coupled to said processor;

an optical head assembly coupled to said excitation light source and to a second carriage assembly, said second carriage assembly providing translation of said optical head assembly along a second axis substantially orthogonal to said first axis, said second carriage assembly coupled to said processor;

a detection assembly comprising a detector, a second scanning monochromator, and a second plurality of optical filters within a second filter wheel, said processor coupled to said detection assembly and controlling a detection wavelength of said detection assembly, said detection assembly coupled to said optical head assembly;

a heater coupled to said processor,

a temperature monitor coupled to said processor,

an air circulation system;

a distance sensing assembly coupled to said processor, said distance sensing assembly determining a distance between an upper surface of said multi-well multi-assay plate and a lid surface in said sample holding area; and

a third carriage assembly coupled to said processor, wherein said third carriage assembly alters said distance between said upper surface of said multi-well multi-assay plate and said lid surface, wherein a humidity proximate to said multi-well multi-assay plate within said sample holding area is in excess of 90 percent.

13. The sample characterizing instrument of claim 12, wherein a temperature variation within said multi-well multi-assay plate held within said sample holding area is less than 0.20°

C.