Abstract: When a flow of a liquid body around a measuring object is visualized, a first liquid body as a tracer is supplied from a nozzle hole into a flow field of a second liquid body, and a laser beam having a wavelength optically absorbed by the first liquid body is irradiated in a manner such that the laser beam traverse across the flow field. At this point, the irradiation position of the laser beam is controlled in such a manner that the flow field is scanned with the laser beam. On the other hand, the laser beam that has passed through the flow field is received and a position where the first liquid body traverses the laser beam is obtained using the scan intensity signal of the received laser beam so that the flow of the second liquid body is visualized. The position where the first liquid body traverses the laser beam can be obtained based on a position on a time axis where a value of the scan intensity signal is less than a set threshold.

Abstract: Disclosed herein is a fluorescence measuring apparatus capable of determining whether accuracy of measuring fluorescence lifetime is deteriorated or not due to adjustment of the apparatus. The fluorescence measuring apparatus for measuring fluorescence emitted when an objects to be measured are irradiated with laser light includes: a laser light source that irradiates each of the objects to be measured with intensity-modulated laser light; a light-receiving unit that receives fluorescence emitted when each of the objects to be measured is irradiated with the laser light; a signal processing unit that determines a fluorescence lifetime using a signal of the fluorescence received by the light-receiving unit; and a determining unit that determines whether or not a fluorescence lifetime dispersion of the objects caused by amplification of the signal of the fluorescence performed by the light-receiving unit or by the signal processing unit is larger than a predetermined value.

Abstract: A fluorescence detecting device receives fluorescence emitted by n kinds of measurement objects within wavelength bands FLk (k is an integer of 1 to n) set so that the fluorescence intensity of fluorescence emitted by a measurement object k becomes higher than that of fluorescence emitted by the other one or more measurement objects, and acquires fluorescent signals corresponding to the wavelength bands FLk (k is an integer of 1 to n). Each of the fluorescent signals is subjected to frequency-down conversion by mixing it with a modulation signal for modulating the intensity of a laser beam Lk (k=1) corresponding to at least one of the wavelength bands FLk to produce fluorescence data including the phase delay and intensity amplitude of the fluorescent signal. The fluorescence data is corrected to calculate the phase delay and a fluorescence relaxation time is calculated using the phase delay.

Abstract: Disclosed herein is a fluorescence measuring apparatus capable of more accurately measuring fluorescence emitted when an object to be measured is irradiated with laser light. The apparatus for measuring fluorescence emitted when an object to be measured is irradiated with laser light includes: a laser light source that irradiates the object to be measured with laser light; a first light-receiving unit that receives scattered light emitted when the object to be measured is irradiated with the laser light; a second light-receiving unit that receives fluorescence emitted when the object to be measured is irradiated with the laser light; and a signal processing unit that assigns a weight to a signal of the fluorescence received by the second light-receiving unit depending on an intensity of the scattered light received by the first light-receiving unit.

Abstract: When a flow of a liquid body around a measuring object is visualized, a first liquid body as a tracer is supplied from a nozzle hole into a flow field of a second liquid body, and a laser beam having a wavelength optically absorbed by the first liquid body is irradiated in a manner such that the laser beam traverse across the flow field. At this point, the irradiation position of the laser beam is controlled in such a manner that the flow field is scanned with the laser beam. On the other hand, the laser beam that has passed through the flow field is received and a position where the first liquid body traverses the laser beam is obtained using the scan intensity signal of the received laser beam so that the flow of the second liquid body is visualized. The position where the first liquid body traverses the laser beam can be obtained based on a position on a time axis where a value of the scan intensity signal is less than a set threshold.

Abstract: A fluorescence detecting method includes the steps of collecting a first fluorescence signal of the fluorescence received by a light receiving unit when the analyte passes a position irradiated with a laser beam, collecting a second fluorescence signal of the fluorescence received by the light receiving unit in the absence of the analyte at the position irradiated with the laser beam, and adjusting a first phase difference information on the first fluorescence signal with respect to the modulation signal by using a second phase difference information on the second fluorescence signal with respect to the modulation signal to obtain a third phase difference information on the fluorescence signal of the fluorescence, and obtaining a fluorescence relaxation time constant of the fluorescence based on the third phase difference information thus obtained.

Abstract: Fluorescence detection device employed in a flow site meter emits laser light intensity-modulated by a modulation signal and acquires the fluorescence signal of fluorescence emitted from a measurement object passing through a measurement point of the laser light. The device generates the reference signal, separately from the modulation signal, the reference signal having a frequency different from the frequency of the modulation signal and having a phase synchronized with a phase of the modulation. The device determines fluorescence relaxation time of the measurement object from the fluorescence signal using the reference signal.

Abstract: Disclosed herein is a method for measuring FRET by irradiating with laser light a measurement sample. FRET is transfer of energy from a first molecule to a second molecule. The first molecule and the second molecule are included in the measurement sample in which ligands are bound to receptors. The method includes the steps of: irradiating the measurement sample with laser light; measuring fluorescence emitted by the measurement sample; calculating a fluorescence lifetime of the first molecule; calculating a binding ratio; setting a binding condition for the measurement sample; and calculating a dissociation constant. In the dissociation constant calculating step, the dissociation constant is determined by using a least-squares method to fit a function having, as variables, a total concentration of the receptor in the measurement sample and the dissociation constant to the binding ratio calculated in the binding ratio calculating step.

Abstract: A fluorescence detection device for a flow site meter emits laser light intensity-modulated in accordance with a modulation signal and acquires a fluorescent signal of fluorescence emitted from a measurement object that passes through a measurement point of the laser light. The fluorescence detection device generates, separately from the modulation signal, a reference signal having a frequency different from a frequency of the modulation signal and a phase in synchronization with a phase of the modulation signal. The fluorescence detection device determines a fluorescent relaxation time of the measurement object from the fluorescent signal by using the reference signal.

Abstract: Disclosed herein is a fluorescence measuring apparatus capable of determining whether accuracy of measuring fluorescence lifetime is deteriorated or not due to adjustment of the apparatus. The fluorescence measuring apparatus for measuring fluorescence emitted when an objects to be measured are irradiated with laser light includes: a laser light source that irradiates each of the objects to be measured with intensity-modulated laser light; a light-receiving unit that receives fluorescence emitted when each of the objects to be measured is irradiated with the laser light; a signal processing unit that determines a fluorescence lifetime using a signal of the fluorescence received by the light-receiving unit; and a determining unit that determines whether or not a fluorescence lifetime dispersion of the objects caused by amplification of the signal of the fluorescence performed by the light-receiving unit or by the signal processing unit is larger than a predetermined value.

Abstract: Disclosed herein is a fluorescence measuring apparatus capable of more accurately measuring fluorescence emitted when an object to be measured is irradiated with laser light. The apparatus for measuring fluorescence emitted when an object to be measured is irradiated with laser light includes: a laser light source that irradiates the object to be measured with laser light; a first light-receiving unit that receives scattered light emitted when the object to be measured is irradiated with the laser light; a second light-receiving unit that receives fluorescence emitted when the object to be measured is irradiated with the laser light; and a signal processing unit that assigns a weight to a signal of the fluorescence received by the second light-receiving unit depending on an intensity of the scattered light received by the first light-receiving unit.

Abstract: Disclosed herein is a fluorescence detecting apparatus. The fluorescence detecting apparatus includes a light-receiving element that receives fluorescence emitted from an object to be measured irradiated with laser light modulated at a predetermined frequency and outputs a fluorescence signal at an adjusted output level; a signal processing unit that mixes the outputted fluorescence signal and a modulation signal with the frequency to generate fluorescence data including information about phase and intensity; and an analyzing device that calculates a first phase shift of the fluorescence emitted from the object to be measured with respect to the modulation signal, calculates a second phase shift by correcting the calculated first phase shift depending on conditions for adjusting the output level, and calculates a fluorescence relaxation time of the fluorescence emitted from the object to be measured using the calculated second phase shift.

Abstract: Among donor molecules labeling protein in living cells to be measured, the rate of donor molecules binding to an acceptor molecule and occurring FRET is determined. In a plurality of previous measurement samples having different ratios of first molecule concentration to second molecule concentration, a fluorescence lifetime of the first molecule are calculated and the fluorescence lifetime minimum value of the first molecule is calculated. The samples are irradiated with a laser beam having time-modulated intensity and the fluorescence emitted by the laser-irradiated measurement samples are measured. By using the fluorescent signals thus measured, the fluorescence lifetime of the first molecule is calculated. By using the fluorescence lifetime minimum value of the first molecule and the fluorescence lifetime of the first molecule that is calculated above, the rate of the first molecules occurring FRET in the first molecules in the measurement samples is calculated.

Abstract: A fluorescence emitted by a measurement object at a measurement point is measured. When the fluorescence is measured, a measurement object is irradiated with laser light whose intensity is time-modulated by using a modulation signal at a predetermined frequency. Then, the fluorescence emitted by the measurement object is formed to a flux of the fluorescence having uniform distribution of light intensity, and a plurality of partial fluorescent signals are generated by receiving a plurality of divided portions of the flux of the fluorescence. At least some of the partial fluorescent signals are added altogether to generate a single fluorescent signal. Finally, a fluorescence relaxation time of the fluorescence emitted by the measurement object is calculated from the generated fluorescent signal by using the modulation signal. When fluorescence intensity of the fluorescence calculated from the fluorescent signal exceeds a predetermined threshold, the partial fluorescent signals to be added are limited in number.

Abstract: A fluorescence detecting device receives fluorescence emitted by n kinds of measurement objects within wavelength bands FLk (k is an integer of 1 to n) set so that the fluorescence intensity of fluorescence emitted by a measurement object k becomes higher than that of fluorescence emitted by the other one or more measurement objects, and acquires fluorescent signals corresponding to the wavelength bands FLk (k is an integer of 1 to n). Each of the fluorescent signals is subjected to frequency-down conversion by mixing it with a modulation signal for modulating the intensity of a laser beam Lk (k=1) corresponding to at least one of the wavelength bands FLk to produce fluorescence data including the phase delay and intensity amplitude of the fluorescent signal. The fluorescence data is corrected to calculate the phase delay and a fluorescence relaxation time is calculated using the phase delay.

Abstract: In order to remove autofluorescence emitted by a measurement object, fluorescence of the measurement object within a first wavelength band is first received. The first wavelength band is set so that the intensity of fluorescence emitted by the measurement object irradiated with intensity-modulated laser light is higher than that of autofluorescence emitted by the measurement object irradiated with the laser light. Then, the autofluorescence within a second wavelength band different from the first wavelength band is received. A generated fluorescent signal of the first fluorescence and a generated fluorescent signal of the autofluorescence are mixed with a modulation signal for modulating the laser light to produce first fluorescence data and autofluorescence data, respectively. The autofluorescence data is multiplied by a predetermined constant, and the thus obtained result is subtracted from the first fluorescence data to produce third fluorescence data.

Abstract: Fluorescence detection device employed in a flow site meter emits laser light intensity-modulated by a modulation signal and acquires the fluorescence signal of fluorescence emitted from a measurement object passing through a measurement point of the laser light. The device generates the reference signal, separately from the modulation signal, the reference signal having a frequency different from the frequency of the modulation signal and having a phase synchronized with a phase of the modulation. The device determines fluorescence relaxation time of the measurement object from the fluorescence signal using the reference signal.

Abstract: A fluorescence detection device for a flow site meter emits laser light intensity-modulated in accordance with a modulation signal and acquires a fluorescent signal of fluorescence emitted from a measurement object that passes through a measurement point of the laser light. The fluorescence detection device generates, separately from the modulation signal, a reference signal having a frequency different from a frequency of the modulation signal and a phase in synchronization with a phase of the modulation signal. The fluorescence detection device determines a fluorescent relaxation time of the measurement object from the fluorescent signal by using the reference signal.

Abstract: Provided are a fluorescence detecting method and a fluorescence detecting device for calculating the fluorescence relaxation time constant more accurately than in the prior art when fluorescence emitted from an analyte is detected by applying laser beam. When the analyte passes the position irradiated with laser beam modulated in intensity by a modulation signal of a predetermined frequency, a first fluorescence signal of fluorescence received by a light-receiving means is collected. A second fluorescence signal of the fluorescence received by the light-receiving means is collected in a state in which the analyte is not in the position irradiated with the laser beam after the analyte has passed the position irradiated with the laser beam.

Abstract: A fluorescence detecting device irradiates an object to be measured with a laser beam, receives fluorescence generated from the object and processes a fluorescence signal generated when receiving the fluorescence. The device includes a laser light source section outputting the laser beam for irradiating the object, a light receiving section outputting the fluorescence signal of the fluorescence generated by the irradiated object, a light source control section generates a modulation signal having a frequency in order to time-modulate an intensity of the laser beam, and a processing section that calculates a fluorescence relaxation time of the fluorescence of the object based on the fluorescence signal output from the light receiving section. From the detection values acquired by the device including the phase information on the fluorescence, the intensity of the fluorescence is calculated.