Real-time optical system for polymerase chain reaction

Abstract

An improved device and system for facilitating polymerase chain reaction including a light source, detector, waveguide, and filters that occupy minimal space and facilitate reduced sample read time and rapid reading of multiple light wavelengths.

What is claimed is: 
     
         1 . An instrument for performing polymerase chain reaction with real-time detection comprising:
 a) a polymerase chain reaction instrument that includes a sample holder having one or more sample wells, wherein the one or more sample wells are configured to receive one or more sample tubes that each have at least one portion that is generally optically transparent, and that receives a biological sample having a nucleic acid to be amplified and at least one fluorescing agent that interacts with the nucleic acid during amplification and that emits light upon excitation by light of a known wavelength;   b) at least one light emitting diode device that is carried on at least one support substrate, is in electrical communication with a power source, is adapted to emit light at a plurality of different wavelengths, and is located below the sample holder so that the sample holder receives light emitted from the at least one light emitting diode device at a bottom of the sample holder;   c) at least one photodiode detector device located below the sample holder and which is adapted to issue signals based upon intensity of light it receives;   d) a light transmission assembly that includes at least one waveguide which is multi-branched and extends towards or partially into the one or more sample wells of the sample holder, wherein the al least one waveguide includes:
 i) at least one first excitation fork portion that extends between the sample holder and the at least one light emitting diode device for transmitting light emitted from the at least one light emitting diode device to the biological sample contained in the sample holder to excite the at least one fluorescing agent; and 
   ii) at least one second emission fork portion that extends between the sample holder and the at least one photodiode detector device for transmitting light emitted by the at least one fluorescing agent upon its excitation and having a first end that is proximate the sample holder and a second end that is proximate the at least one photodiode detector device; and   e) one or more emission filters disposed between the second end of the at least one second emission fork portion and the at least one photodiode detector device and is adapted to filter the light emitted by the at least one fluorescing agent across a plurality of bandwidths so that the wavelengths of light received by the at least one photodiode detector device are known, wherein the one or more filters include a linear variable band pass filter, series of bandpass filters, or multiple band bandpass filter.   
     
     
         2 - 20 . (canceled) 
     
     
         21 . The instrument of  claim 1 , wherein the instrument includes one or more excitation filters disposed between an end of the first excitation fork portion and the at least one light emitting diode device which are adapted to filter the light emitted by the at least one light emitting diode device into multiple bandwidths for excitation of the biological sample. 
     
     
         22 . The instrument of  claim 1 , wherein the instrument includes a rotatable filter wheel which includes the one or more emission filters. 
     
     
         23 . The instrument of  claim 21 , wherein the instrument includes a rotatable filter wheel which includes the one or more excitation filters. 
     
     
         24 . The instrument of  claim 21 , wherein the instrument includes a rotatable filter wheel which includes the one or more emission filters and the one or more excitation filters. 
     
     
         25 . The instrument of  claim 1 , wherein the instrument includes opposing thermoelectric devices which sandwich the sample holder. 
     
     
         26 . The instrument of  claim 1 , wherein the instrument includes a housing between the sample holder and the at least one support substrate which receives the at least one waveguide. 
     
     
         27 . The instrument of  claim 26 , wherein the housing includes one or more chambers which isolate the at least one photodiode detector device from the at least one light emitting diode device. 
     
     
         28 . The instrument of  claim 1 , wherein the at least one waveguide partially extends into the one or more sample wells. 
     
     
         29 . The instrument of  claim 1 , wherein the at least one waveguide includes one or more fiber optic bundles. 
     
     
         30 . The instrument of  claim 1 , wherein the at least one waveguide includes a joined armed which extends into at least one bifurcated portion, and the bifurcated portion includes the at least one first excitation fork portion and the at least one second emission fork portion. 
     
     
         31 . The instrument of  claim 1 , wherein the at least one light emitting diode device is an integrated assembly of LEDs or a compact group of light emitting diodes. 
     
     
         32 . The instrument of  claim 1 , wherein the at least one light emitting diode device is less than 1 cm on each side. 
     
     
         33 . The instrument of  claim 1 , wherein the at least one photodiode detector device is a photodiode pixel array or compact grouping of photodiodes, such that the wavelengths of light received across individual pixels or photodiodes are of known wavelengths corresponding to one or more different fluorescent agents present within the one or more sample tubes. 
     
     
         34 . The instrument of  claim 1 , wherein the one or more sample tubes are optically transparent along a bottom portion of the one or more sample tubes. 
     
     
         35 . The instrument of  claim 1 , wherein each of the at least one light emitting diode device includes at least 4 light emitting diode elements. 
     
     
         36 . The instrument of  claim 1 , at least one converging lens is present between the second end of the at least one second emission fork portion and the at least one photodiode detector device. 
     
     
         37 . The instrument of  claim 1 , wherein one or more emission filters are configured to be optically aligned the at least one photodiode array detector. 
     
     
         38 . The instrument of  claim 26 , wherein the housing includes an upper portion aligned with the sample holder, and a base portion having a cavity therein through which the at least one waveguide is passed. 
     
     
         39 . The instrument of  claim 1 , wherein for each sample there is one or more of the at least one light emitting diode device, one or more of the at least one photodiode detector device, or both.