Systems and methods for fluorescence detection with a movable detection module

Abstract

A fluorescence detection apparatus for analyzing samples located in a plurality of wells in a thermal cycler and methods of use are provided. In one embodiment, the apparatus includes a support structure attachable to the thermal cycler and a detection module movably mountable on the support structure. The detection module includes one or more channels, each having an excitation light generator and an emission light detector both disposed within the detection module. When the support structure is attached to the thermal cycler and the detection module is mounted on the support structure, the detection module is movable so as to be positioned in optical communication with different ones of the plurality of wells. The detection module is removable from the support structure to allow easy replacement.

1 . (canceled) 
     
     
         2 . A fluorescence detection module comprising:
 a detection module housing having a plurality of openings at a first end;   a mechanical connector disposed on an outside surface of the detection module housing at a second end opposite the first end, the mechanical connector being configured to detachably attach the detection module to a movable shuttle mounted inside a thermal cycler in an orientation such that, by moving the movable shuttle, the openings at the first end of the detection module housing are positionable in optical communication with a plurality of sample wells inside the thermal cycler; and   a plurality of excitation/detection pairs disposed within the detection module housing, each excitation/detection pair being separated from each other excitation detection pair by opaque walls, each excitation/detection pair including:
 an excitation light generator fixedly mounted inside the opaque walls; 
 an emission light detector fixedly mounted inside the opaque walls; and 
 one or more optical components fixedly mounted inside the opaque walls and arranged to direct light from the excitation light generator toward a respective one of the openings at the first end of the detection module housing and to direct light from the respective one of the openings toward the emission light detector. 
   
     
     
         3 . The fluorescence detection module of  claim 2  wherein each excitation light generator comprises a light-emitting diode (LED). 
     
     
         4 . The fluorescence detection module of  claim 2  wherein each excitation light generator is configured to generate light at a different range of wavelengths. 
     
     
         5 . The fluorescence detection module of  claim 2  wherein each emission light detector is configured to detect light at a different range of wavelengths. 
     
     
         6 . The fluorescence detection module of  claim 2  wherein the one or more optical components of each excitation/detection pair include a beam splitter oriented such that light from the excitation light generator of the excitation/detection pair is directed toward the respective one of the openings and light entering through the respective one of the openings is directed toward the emission light detector of the excitation/detection pair. 
     
     
         7 . The fluorescence detection module of  claim 6  wherein the beam splitter is highly transparent to light of an excitation wavelength generated by the excitation light generator and highly reflective to light of a detection wavelength. 
     
     
         8 . The fluorescence detection module of  claim 6  wherein the one or more optical components of each excitation/detection pair further include a lens to focus light from the excitation light generator onto the beam splitter. 
     
     
         9 . The fluorescence detection module of  claim 6  wherein the one or more optical components of each excitation/detection pair further include a lens to focus light from the beam splitter onto the emission light detector. 
     
     
         10 . The fluorescence detection module of  claim 2  wherein the plurality of openings are arranged such that each excitation/detection pair is simultaneously positionable in optical communication with a different one of the sample wells. 
     
     
         11 . The fluorescence detection module of  claim 2  wherein the plurality of openings are arranged such that when a first one of the excitation/detection pairs is positioned in optical communication with one of the sample wells, a different one of the excitation/detection pairs is not in optical communication with any of the sample wells. 
     
     
         12 . The fluorescence detection module of  claim 2  wherein the mechanical connector includes a receptacle for a ball plunger. 
     
     
         13 . The fluorescence detection module of  claim 2  further comprising:
 an electrical connector disposed on the detection module at the second end. 
 
     
     
         14 . The fluorescence detection module of  claim 13  wherein the electrical connector includes electrical signal paths to pass control signals to activate and deactivate the excitation light generators and to pass data signals from the emission light detectors. 
     
     
         15 . A method of calibrating a movable detection module in a fluorescence detection apparatus, the method comprising:
 providing a lid heater having a plurality of openings to permit optical communication with a plurality of sample wells, the lid heater having a plurality of calibration locations arranged between the openings, wherein each calibration location includes a material that provides a known fluorescence response;   attaching a detection module to a movable shuttle inside a lid of the fluorescence detection apparatus, wherein the detection module includes a plurality of excitation/detection pairs, each excitation/detection pair being separated from each other excitation detection pair by opaque walls, each excitation/detection pair including an excitation light generator, an emission light detector, and one or more optical components arranged to direct light from the excitation light generator toward a respective one of a plurality of openings at a first end of the detection module housing and to direct light from the respective one of the openings toward the emission light detector;   with the lid closed, operating the movable shuttle to position the detection module such that a first one of the excitation/detection pairs is in optical communication with a first one of the calibration locations;   obtaining a first calibration measurement for the first one of the excitation/detection pairs;   operating the movable shuttle to reposition the detection module such that a second one of the excitation/detection pairs is in optical communication with a second one of the calibration locations;   obtaining a second calibration measurement for the second one of the excitation/detection pairs;   operating the movable shuttle to reposition the detection module such that the first one of the excitation/detection pairs is in optical communication with a first one of the sample wells; and   interrogating the first one of the sample wells using the first one of the excitation/detection pairs.   
     
     
         16 . The method of  claim 15  wherein interrogating the first one of the sample wells using the first one of the excitation/detection pairs includes briefly flashing the excitation light source of the first one of the excitation/detection pairs and reading a signal from the emission light detector of the first one of the excitation/detection pairs. 
     
     
         17 . The method of  claim 15  wherein, when the first one of the excitation/detection pairs is in optical communication with the first one of the sample wells, the second one of the excitation/detection pairs is in optical communication with a second one of the sample wells, the method further comprising:
 while the first one of the excitation/detection pairs is in optical communication with a first one of the sample wells, interrogating the second one of the sample wells using the second one of the excitation/detection pairs. 
 
     
     
         18 . The method of  claim 17  wherein interrogating the first one of the sample wells using the first one of the excitation/detection pairs and interrogating the second one of the sample wells using the second one of the excitation/detection pairs are performed sequentially. 
     
     
         19 . The method of  claim 17  wherein interrogating the first one of the sample wells using the first one of the excitation/detection pairs and interrogating the second one of the sample wells using the second one of the excitation/detection pairs are performed concurrently. 
     
     
         20 . The method of  claim 15  wherein, when the first one of the excitation/detection pairs is in optical communication with the first one of the sample wells, the second one of the excitation/detection pairs is not in optical communication with any of the sample wells, the method further comprising:
 subsequently to interrogating the first one of the sample wells, operating the movable shuttle to reposition the detection module such that a second one of the excitation/detection pairs is in optical communication with a second one of the sample wells; and 
 interrogating the second one of the sample wells using the second one of the excitation/detection pairs. 
 
     
     
         21 . The method of  claim 15  further comprising:
 subsequently to interrogating the first one of the sample wells using the first one of the excitation/detection pairs, operating the movable shuttle to reposition the detection module such that a second one of the excitation/detection pairs is in optical communication with the first one of the sample wells; and 
 interrogating the first one of the sample wells using the second one of the excitation/detection pairs.