High speed cross-correlation frequency domain fluorometry-phosphorimetry
First Claim
1. In apparatus for cross-correlation frequency domain fluorometry-phosphorimetry, which comprises:
- a source of electromagnetic radiation;
means for amplitude modulating the electromagnetic radiation at a first frequency;
means for directing the amplitude-modulated electromagnetic radiation at a sample;
means for detecting the luminescence of the sample;
means for providing a signal coherent with amplitude modulated signals produced by said amplitude modulating means, at a second frequency, to said detecting means;
means for modulating the gain of said detecting means, or multiplying the output of said detecting means, by said signal;
said second frequency being different from said first frequency; and
means for deriving a resultant signal from said electromagnetic radiation and said detecting means at a frequency of the difference between said first and second frequencies, to detect phase shift and modulation changes of said luminescence from that of said electromagnetic radiation;
the improvement comprising, in combination;
means for sequentially performing runs of said cross-correlation frequency domain fluorometry-phosphorimetry at sequentially differing first and second frequencies;
means for detecting the intensities of signal responses of said runs at the respective cross-correlation frequency which is the difference of the respective first and second frequencies used in each run; and
means for prolonging the detecting of each signal response at each of said differing first and second frequencies, until an integrated signal with a specified standard deviation has been acquired at each of said differing first and second frequencies.
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Abstract
Apparatus for cross-correlation frequency domain fluorometry and/or phosphorimetry in which means are provided for sequentially performing runs of the cross correlation frequency domain fluorometry and/or phosphorimetry at sequentially differing first and second frequencies. The intensities of signal responses of the runs are detected at the respective cross-correlation frequency in each run. The detection of the signal response is prolonged in each run until an integrated signal with a specified standard deviation has been acquired at each of the differing runs. Preferably the sequential runs are automatically executed by a program. Also, the waveforms sensed by deriving the resultant signal response in each run are folded. That is: corresponding segments of the waveforms are superimposed to obtain an average waveform value for each run having an increased signal to noise ratio over the individual waveform segments. Also, preferably, a software-created variable frequency digital filter is used to filter signal responses at the cross-correlation frequency.
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Citations
27 Claims
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1. In apparatus for cross-correlation frequency domain fluorometry-phosphorimetry, which comprises:
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a source of electromagnetic radiation; means for amplitude modulating the electromagnetic radiation at a first frequency; means for directing the amplitude-modulated electromagnetic radiation at a sample; means for detecting the luminescence of the sample; means for providing a signal coherent with amplitude modulated signals produced by said amplitude modulating means, at a second frequency, to said detecting means; means for modulating the gain of said detecting means, or multiplying the output of said detecting means, by said signal; said second frequency being different from said first frequency; and
means for deriving a resultant signal from said electromagnetic radiation and said detecting means at a frequency of the difference between said first and second frequencies, to detect phase shift and modulation changes of said luminescence from that of said electromagnetic radiation;the improvement comprising, in combination;
means for sequentially performing runs of said cross-correlation frequency domain fluorometry-phosphorimetry at sequentially differing first and second frequencies;
means for detecting the intensities of signal responses of said runs at the respective cross-correlation frequency which is the difference of the respective first and second frequencies used in each run; and
means for prolonging the detecting of each signal response at each of said differing first and second frequencies, until an integrated signal with a specified standard deviation has been acquired at each of said differing first and second frequencies. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. In apparatus for cross-correlation frequency domain fluorometry-phosphorimetry, which comprises:
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a source of electromagnetic radiation; means for amplitude modulating the electromagnetic radiation at a first frequency; means for directing the amplitude-modulated electromagnetic radiation at a sample; means for detecting the luminescence of the sample; means for providing a signal coherent with amplitude modulated signals produced by said amplitude modulating means, at a second frequency, to said detecting means; means for modulating the gain of said detecting means or multiplying the output of said detecting means by said signal; said second frequency being different from said first frequency; and
means for deriving a resultant signal from said electromagnetic radiation and said detecting means at a frequency of the difference between said first and second frequencies, to detect phase shift and modulation changes of said luminescence from that of said electromagnetic radiation;the improvement comprising, in combination;
means for automatically and sequentially performing runs of said cross-correlation frequency domain fluorometry-phosphorimetry at sequentially differing first and second frequencies;
means for detecting the intensities of signal responses of said runs at the respective cross-correlation frequency which is the difference of the respective first and second frequencies used in each run; and
means for prolonging the detecting of each said signal response at each of said cross-correlation frequencies until an integrated signal with a specific standard deviation has been acquired at each of said different cross-correlation frequencies;
said resultant signal deriving means comprising variable frequency digital filter means capable of being set to filter signal responses at substantially the cross-correlation frequencies. - View Dependent Claims (10, 11, 12, 13)
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14. In apparatus for cross-correlation frequency domain fluorometry-phosphorimetry, which comprises:
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a source of electromagnetic radiation; means for amplitude modulating the electromagnetic radiation at a first frequency; means for directing the amplitude-modulated electromagnetic radiation at a sample; means for detecting the luminescence of the sample; means for providing a signal coherent with amplitude modulated signals produced by said amplitude modulating means, at a second frequency, to said detecting means; means for modulating the gain of said detecting means or multiplying the output by said detecting means by said signal; said second frequency being different from said first frequency; and
means for deriving a resultant signal from said electromagnetic radiation and said detecting means at a frequency of the difference between said first and second frequencies, to detect phase shift and modulation changes of said luminescence from that of said electromagnetic radiation;the improvement comprising, in combination;
means for synchronizing the acquisition of data waveforms sensed by said resultant signal deriving means in each run, with the phase of the signal modulating the electromagnetic radiation at said first frequency, and for superimposing corresponding segments of said waveforms thus sensed to obtain an average waveform value for each run having an increased signal to noise ratio over the individual waveform segments, said synchronizing means comprising variable bandwidth digital filter means. - View Dependent Claims (15)
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16. In a method for frequency domain cross-correlation fluorometry-phosphorimetry which comprises the steps of:
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providing a source of electromagnetic radiation; amplitude modulating the electromagnetic radiation at a first frequency; directing the amplitude-modulated electromagnetic radiation at a sample; detecting with a detector the luminescence of the sample while modulating the gain of said detector or multiplying the output of said detector with a signal at a second frequency to said detector;
with said signal at a second frequency being coherent with the modulation of said electromagnetic radiation and said second frequency being different from said first frequency; andderiving a resultant signal from said electromagnetic radiation and said detector at a frequency of the difference between said first and second frequencies, to detect phase shift and modulation of said luminescence from that of said electromagnetic radiation; the improvement comprising, in combination;
sequentially and automatically performing runs of said cross-correlation frequency domain fluorometry-phosphorimetry at sequentially differing values of said first and second frequencies;
detecting the intensities of signal responses of said runs at the respective frequency which is the difference of the respective first and second frequencies of each run; and
prolonging the time of said detecting of each signal response at each of said different first and second frequencies until an integrated signal with a specific standard deviation has been acquired at each of said differing first and second frequencies. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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24. In a method for frequency domain cross-correlation fluorometry-phosphorimetry which comprises the steps of:
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providing a source of electromagnetic radiation; amplitude modulating the electromagnetic radiation at a first frequency; directing the amplitude-modulated electromagnetic radiation at a sample; detecting with a detector the luminescence of the sample while modulating the gain or multiplying the output of said detector with a signal at a second frequency to said detector;
with said signal at a second frequency being coherent with the modulation of said electromagnetic radiation and said second frequency being different from said first frequency; andderiving a resultant signal from said electromagnetic radiation and said detector at a frequency of the difference between said first and second frequencies, to detect phase shift and modulation of said luminescence from that of said electromagnetic radiation; the improvement comprising, in combination; sequentially and automatically performing runs of said cross-correlation frequency domain fluorometry at sequentially differing values of said first and second frequencies;
in which said resultant signal is derived by means comprising variable frequency digital filter means set to filter signal responses at substantially a third frequency which is the difference of the respective first and second frequencies used. - View Dependent Claims (25, 26, 27)
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Specification