Method for analyzing dynamic detectable events at the single molecule level

Abstract

A method to be implemented on or in a computer is disclosed, where the method includes data collection, calibration, candidate selection, and analysis of data streams associated with each candidate to classify single molecule fluorescence resonance energy transfer events. Once classified, the classification can be related to the nature of the events, such as the identification of dNTP incorporation during primer extension to obtain a base read out of an unknown template.

1 . A method for detecting and analyzing events at the single molecule level, where the method comprising the steps of:
 collecting data corresponding to changes in a detectable property of a detectable entity in a sample over time within a viewing volume or field of a detection system, where the data comprises a collection of data frames associated with a plurality of data channels, where the data channels represent different features of the detectable property, and where each frame is an image of the viewing field over a data collection interval comprising a set of data elements representable in a column row matrix format, and where the detectable entity is selected from the group consisting of an atom, a molecule, an ion, an assemblage of atoms, molecules and/or ions, a plurality of atoms, a plurality of molecules, a plurality of ions, and/or a plurality of assemblages,   forwarding the data frames to a processing unit, where the data frames are stored along with data associated with the detection of the detectable property including sample data, time/data and detector data,   generating a calibration transformation adapted to register data elements in one data channel with corresponding data elements in the other data channels,   averaging a value of the detectable property for each data element over all of the frames from one data channel to produce a averaged image, where each data element in the averaged image includes the average value of detectable property across all the frames,   identifying data elements in the averaged images having a value of the detectable property above a threshold value to produce a list of potential active entity candidates,   retrieving and storing candidate data traces, one trace for each data element in a n×n data element array centered at each identified candidate,   retrieving and storing noise data traces from a plurality of data elements within an m×m data element array centered at each identified candidate excluding the data elements of the n×n array, where the noise data traces represent local noise associated with each candidate,   filtering the candidates to find candidates that satisfy a set of selection criteria or passing a set of rejection criteria,   retrieving and storing other channel data traces, one trace for each data element in a n\n data element array centered at data element of the other data channels corresponding to the candidate,   retrieving and storing other channel noise data traces from a plurality of data elements within an m×m data element array centered at data element of the other data channels corresponding to the candidate excluding the data elements of the n×n array, where the noise data traces represent local noise associated with other data channels,   smoothing the traces and forming hybrid traces, one hybrid trace for each candidate, for each candidate noise, for each other channel corresponding candidate data and for each other channel noise data,   identifying hybrid traces that evidence correlated or anti-correlated changes in the detectable property for the candidate traces and the corresponding other channel traces to produce an event list, and   classifying the event list into a class of events, and   storing the classified list of events.   
     
     
         2 . The method of  claim 1 , wherein at least one component of the entities include a fluorophore and the detectable property is fluorescence. 
     
     
         3 . The method of  claim 1 , wherein at least one component of the entities include a donor fluorophore, at least one component of the entities include an acceptor fluorophore and the detectable property is fluorescence derived from fluorescence resonance energy transfer. 
     
     
         4 . The method of  claim 1 , wherein each detectable entity comprises replication complex including a polymerase, a template, a primer and nucleotides for the polymerase, where the polymerase, template, and/or primer includes a donor fluorophore and at least one nucleotide type including an acceptor fluorophore forming a FRET pair and the detectable property is fluorescence derived from fluorescence resonance energy transfer. 
     
     
         5 . The method of  claim 4 , where the identified hybrid traces are anti-correlated. 
     
     
         6 . The method of  claim 1 , wherein each detectable entity comprises replication complex including a polymerase, a template, a primer and nucleotides for the polymerase, where the polymerase, template, and/or primer includes a donor fluorophore and at least two nucleotide types including acceptor fluorophores forming a FRET pair, where the acceptor fluorophores are the same or different, and the detectable property is fluorescence derived from fluorescence resonance energy transfer. 
     
     
         7 . The method of  claim 6 , where the identified hybrid traces are anti-correlated. 
     
     
         8 . The method of  claim 1 , wherein each detectable entity comprises replication complex including a polymerase, a template, a primer and nucleotides for the polymerase, where the polymerase, template, and/or primer includes a donor fluorophore and at least three nucleotide types including acceptor fluorophores forming a FRET pair, where the acceptor fluorophores are the same or different, and the detectable property is fluorescence derived from fluorescence resonance energy transfer. 
     
     
         9 . The method of  claim 8 , where the identified hybrid traces are anti-correlated. 
     
     
         10 . The method of  claim 1 , wherein each detectable entity comprises replication complex including a polymerase, a template, a primer and nucleotides for the polymerase, where the polymerase, template, and/or primer includes a donor fluorophore and each nucleotide type including acceptor fluorophores forming a FRET pair, where the acceptor fluorophores are the same or different, and the detectable property is fluorescence derived from fluorescence resonance energy transfer. 
     
     
         11 . The method of  claim 10 , where the identified hybrid traces are anti-correlated.