Differential Dissociation and Melting Curve Peak Detection
Systems and methods are provided for processing a melting or dissociation curve of a DNA or other sample, for example, during PCR processing. In some embodiments, detection of the melting point and melting curve behavior can be enhanced by taking a derivative of the curve, and detecting peaks in the differential dissociation curve. In some embodiments, the derivative operation can comprise the use of edge-processing, or other detection algorithms. In some embodiments, the dissociation analysis can comprise removing low-frequency (or pedestal) components of the differential dissociation curve. In some embodiments, the differential dissociation curve can exhibit a smoothed or more regular appearance than the raw detected data.
1 . A method for determining the differential dissociation curve of at least one sample, comprising:
interpolating emission measurement data of the at least one sample taken at uneven temperature intervals into data at equally-spaced temperature intervals; and
generating a differential dissociation curve by generating a derivative of the emission measurement data.
2 . The method of claim 1 , further comprising detecting at least one peak in the differential dissociation curve.
3 . The method of claim 1 , further comprising modifying the differential dissociation curve.
4 . The method of claim 1 , further comprising generating a power spectrum of the interpolated emission measurement data.
5 . The method of claim 1 , wherein the derivative comprises a first-order derivative.
6 . The method of claim 1 , further comprising performing a frequency-domain transform on the interpolated emission measurement data.
7 . The method of claim 1 , wherein the at least one sample comprises a plurality of samples each having associated emission measurement data.
8 . A system for determining the differential dissociation curve of at least one sample, comprising:
an input unit for receiving emission data of at least one sample taken at uneven temperature intervals; and
a processor, communicating with the input unit, the processor being configured to
interpolate the emission measurement data of the at least one sample taken at uneven temperature intervals into data at equally-spaced temperature intervals, and
generate a differential dissociation curve by generating a derivative of the emission measurement data.
9 . The system of claim 8 , wherein the processor is further configured to detect at least one peak in the differential dissociation curve.
10 . The system of claim 8 , wherein the processor is further configured to modify the differential dissociation curve.
11 . The system of claim 10 , wherein the modifying comprises removing emission measurement data associated with peaks that fall below a peak detection threshold.
12 . A differential dissociation curve generated for at least one sample, the differential dissociation curve being generated by a method comprising:
interpolating emission measurement data of the at least one sample taken at uneven temperature intervals into data at equally-spaced temperature intervals; and
generating a differential dissociation curve by generating a derivative of the emission measurement data.
13 . The differential dissociation curve of claim 12 , wherein the method further comprises generating a power spectrum of the interpolated emission measurement data.
14 . The differential dissociation curve of claim 13 , wherein generating a power spectrum comprises generating a normalized variance of the power spectrum and removing the emission measurement data of the at least one sample when the normalized variance of the power spectrum exceeds a predetermined threshold.
15 . A computer-readable medium, the computer-readable medium being readable to execute a method for determining the differential dissociation curve of at least one sample, the method comprising:
interpolating emission measurement data of the at least one sample taken at uneven temperature intervals into data at equally-spaced temperature intervals; and
generating a differential dissociation curve by generating a derivative of the emission measurement data.
16 . The computer-readable medium of claim 15 , wherein the method further comprises modifying the differential dissociation curve.
17 . The computer-readable medium of claim 15 , wherein the method further comprises generating a power spectrum of the interpolated emission measurement data.
18 . The computer-readable medium of claim 15 , wherein the derivative comprises a first-order derivative.
19 . The computer-readable medium of claim 15 , wherein the method further comprises performing a frequency-domain transform on the interpolated emission measurement data.
20 . The computer-readable medium of claim 15 , wherein the differential dissociation curve is generated in connection with a polymerase chain reaction process.