Fluorescence correlation spectroscopy instrument and method of using the same

Abstract

Disclosed is a portable fluorescence correlation spectroscopy instrument that includes an excitation source, at least one of a light focusing element positioned to receive light emitted by the excitation source, a detector for detecting light, the detector positioned to receive light emitted by a sample excited by the excitation source, and a correlator coupled to the detector, the correlator for processing data received at the detector and providing data including autocorrelation data, crosscorrelation data, or a combination thereof.

1 . A fluorescence correlation spectroscopy instrument comprising: 
 an excitation source that emits light along an optical axis extending in a first direction;    a first dichromatic mirror that alters the direction of the optical axis to a second direction different from the first direction;    a first reflective mirror that alters the second direction of the optical axis to a third direction, the third direction being perpendicular to the first direction and the second direction;    a first light focusing element positioned to receive light reflected by the first reflective mirror and to focus the light in a sample volume;    a detector for detecting light, the detector positioned to receive light emitted by a sample excited by the excitation source; and    a correlator coupled to the detector, the correlator for processing data received at the detector and providing data comprising autocorrelation data, crosscorrelation data, or a combination thereof.    
   
   
       2 . A fluorescence correlation spectroscopy instrument comprising: 
 a sample chamber;    an excitation source;    a probe comprising an exit aperture having a diameter no greater than 50 nm, the probe disposed in the sample chamber and positioned to receive light emitted by the excitation source, the probe transmitting light through the exit aperture;    a first light focusing element positioned to receive light emitted by a sample excited by the light emitted from the probe;    a detector positioned to receive light transmitted through the first light focusing element; and    a correlator coupled to the detector, the correlator for processing data received at the detector and providing data comprising autocorrelation data, crosscorrelation data, or a combination thereof.    
   
   
       3 . The fluorescence correlation spectroscopy instrument of  claim 2 , wherein the optical axis of the first light focusing element is positioned in parallel with the optical axis of the probe.  
   
   
       4 . The fluorescence correlation spectroscopy instrument of  claim 2 , wherein the optical axis of the first light focusing element is positioned in a perpendicular relationship to the optical axis of the probe.  
   
   
       5 . The instrument of  claim 2 , wherein the object plane of the first light focusing element is in the near field of the probe.  
   
   
       6 . The instrument of  claim 2 , wherein said probe comprises a tapered end having an aluminized tip.  
   
   
       7 . A fluorescence correlation spectroscopy instrument comprising: 
 an excitation source;    a sample chamber;    a first light focusing element positioned to receive light emitted by the excitation source, and to transmit light to the sample chamber;    a first aspheric lens positioned to receive light emitted by a sample in the sample chamber;    a detector for detecting light, the detector positioned to receive light transmitted through the aspheric lens; and    a correlator coupled to the detector, the correlator for processing data received at the detector and providing data comprising autocorrelation data, crosscorrelation data, or a combination thereof.    
   
   
       8 . The instrument of  claim 7 , further comprising a second aspheric lens positioned to receive light emitted by the excitation source and to transmit the light to the first light focusing element.  
   
   
       9 . A fluorescence correlation spectroscopy instrument comprising: 
 an excitation source;    a sample chamber;    a first light focusing element positioned to receive light emitted by the excitation source and to transmit light to the sample chamber;    a means for pulsing sample through the sample chamber;    a detector for detecting light, the detector adapted to obtain data from the sample chamber when the sample is stationary in the sample chamber; and    a correlator coupled to the detector, the correlator for processing data received at the detector and providing data comprising autocorrelation data, crosscorrelation data, or a combination thereof.    
   
   
       10 . The instrument of  claim 9 , wherein said means for pulsing comprises a pump.  
   
   
       11 . A fluorescence correlation spectroscopy instrument comprising: 
 an excitation source;    a first light focusing element positioned to receive light emitted by the excitation source and to transmit light to a sample;    a means for electrophoretically flowing a sample;    a detector for detecting light, the detector positioned to receive light emitted by a sample excited by the excitation source; and    a correlator coupled to the detector, the correlator for processing data received at the detector and providing data related to the electrophoretic flow rate of particles in the sample.    
   
   
       12 . The instrument of  claim 11 , wherein said means for electrophoretically flowing a sample comprises a power source for inducing electrophoretic flow in the sample.  
   
   
       13 . A fluorescence correlation spectroscopy instrument comprising: 
 an excitation source;    a beam expansion system for expanding the diameter of the beam of light emitted from the excitation source;    a first light focusing element positioned to receive light emitted by the excitation source, and to transmit light to a sample;    a detector for detecting light, the detector positioned to receive light emitted by a sample excited by the excitation source; and    a correlator coupled to the detector, the correlator for processing data received at the detector and providing data comprising autocorrelation data, crosscorrelation data, or a combination thereof.    
   
   
       14 . The instrument of  claim 13 , wherein the beam expansion system comprises at least one of a two-lens beam expansion system and a negative achromatic doublet lens.  
   
   
       15 . The instrument of  claim 1 , wherein the excitation source comprises a diode pumped solid state laser.  
   
   
       16 . The instrument of  claim 1 , wherein the excitation source exhibits less than 3% peak to peak noise.  
   
   
       17 . The instrument of  claim 1 , further comprising a sample flow chamber comprising an input and an output.  
   
   
       18 . The instrument of  claim 17 , wherein the output is coupled to a waste receptacle.  
   
   
       19 . The instrument of  claim 17 , wherein the sample flow chamber comprises at least one of capillary tubing, a cuvette, a cylindrical flow cell, and a flat flow cell.  
   
   
       20 . The instrument of  claim 1 , wherein the instrument is operable in a fixed stage mode.