Patent ID: 9291563
Filing Date: 2016-03-22
CPC Classification: C12Q,G01N

Claim Text:
1. A FRET measurement device comprising: a conduit through which a test sample flows, the test sample comprising: a FRET probe that includes a probe element X labeled with a donor fluorescent substance and a probe element Y labeled with an acceptor fluorescent substance and enables FRET to occur when the probe element X and the probe element Y approach to each other or bind together; and a test object about which it is unknown whether or not it has an approaching/binding property of allowing the probe element X and the probe element Y to approach to each other or bind together or a separating property of separating the probe element X and the probe element Y that are in a state where they adjoin each other or bind together; a light source unit configured to emit, toward the conduit, laser light whose intensity is modulated using a modulation signal; a light-receiving unit configured to receive fluorescence emitted from the FRET probe in the test sample by irradiation with the intensity-modulated laser light and outputs a fluorescent signal; and an analyzing unit configured to: determine, using the fluorescent signal and the modulation signal, a phase difference of donor fluorescence emitted from the donor fluorescent substance with respect to the modulation signal as a first phase difference; a modulation frequency used for the modulation signal in the light source unit being an optimum modulation frequency that maximizes a difference between a second phase difference of donor fluorescence emitted from the donor fluorescent substance with respect to the modulation signal at a time when the FRET occurs and a third phase difference of donor fluorescence emitted from the donor fluorescent substance with respect to the modulation signal at a time when the FRET does not occur.