Abstract: When receiving fluorescence emitted by a measurement object irradiated with laser light emitted from a laser light source unit, a fluorescence detection device generates a modulation signal for modulating the intensity of the laser light and modulates the laser light using the modulation signal. The fluorescence detection device obtains a fluorescent signal of the fluorescence emitted by the measurement object irradiated with the laser light, and calculates, from the fluorescent signal, a fluorescence intensity and the phase delay of the fluorescence with respect to the modulation signal. At the time, the fluorescence detection device controls the operation amounts of the signal level of a DC component of the modulation signal and the gain of amplification just after the output of the fluorescent signal so that the value of a fluorescence intensity signal falls within a preset range.

Abstract: A fluorescence detecting device generates a modulation signal for modulating an intensity of laser light and modulates the laser light by using the modulation signal, when receiving fluorescence emitted by a measurement object irradiated with laser light emitted from a laser light source unit. The fluorescence detecting device obtains a fluorescent signal of the fluorescence emitted by the measurement object irradiated with the laser light and calculates, from the fluorescent signal, the phase delay of the fluorescence with respect to the modulation signal. At the time, the fluorescence detecting device controls the frequency of the modulation signal so that the value of the phase delay comes close to a preset value. The fluorescence detecting device calculates the fluorescence relaxation time of the fluorescence emitted by the measurement object by using a phase delay obtained under the condition of frequency of the modulation signal at the time when the control is settled.

Abstract: In a fluorescence detection device and a fluorescence detection method, forward-scattered light which is scattered from a measurement object irradiated with a laser beam is received and detection signals for informing the measurement object passing through the measurement point and for identifying a focus position of the forward-scattered light are produced. While, fluorescence emitted by the measurement object is received through a collecting lens and a light-reception signal of the fluorescence is outputted. The fluorescence intensity level is outputted based on the outputted light-reception signal and the produced detection signals. A focus position of the forward-scattered light is identified from the produced detection signals and the light reception-signal is corrected using a correction coefficient corresponding to the identified focus position.

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: 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: In a fluorescence detection device and a fluorescence detection method, forward-scattered light which is scattered from a measurement object irradiated with a laser beam is received and detection signals for informing the measurement object passing through the measurement point and for identifying a focus position of the forward-scattered light are produced. While, fluorescence emitted by the measurement object is received through a collecting lens and a light-reception signal of the fluorescence is outputted. The fluorescence intensity level is outputted based on the outputted light-reception signal and the produced detection signals. A focus position of the forward-scattered light is identified from the produced detection signals and the light reception-signal is corrected using a correction coefficient corresponding to the identified focus position.

Abstract: When FRET efficiency is measured quantitatively by removing uncertain elements of fluorescence detection information, calibration information prestored in a storage means while including at least the leak rate of donor fluorescence component emitted from a donor molecule, the leak rate of acceptor fluorescence component emitted from an acceptor molecule, and the non-FRET fluorescence lifetime of the donor fluorescence component when FRET is not generated out of the fluorescence of a measurement object sample is acquired. The FRET fluorescence lifetime of the donor fluorescence component is then determined using the intensity information and phase information of fluorescence of the measurement object sample, the leak rate of donor fluorescence component and the leak rate of acceptor fluorescence component, thus determining the FRET fluorescence efficiency.

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.

Abstract: When FRET (Fluorescence Resonance Energy Transfer) detection of a large number of samples is performed in a short time for a sample consisting of a donor molecule and an acceptor molecule, the donor molecule is irradiated at first with first laser light used for exciting a donor molecule subjected to intensity modulation at a frequency of f+?f, the accepter molecule is irradiated with second laser light used for exciting an acceptor molecule subjected to intensity modulation at a frequency of f, and fluorescence emitted from the accepter molecule is received. From a fluorescence signal thus received, a first signal component of fluorescence emitted from the accepter molecule through FRET, and a second signal component of fluorescence emitted from an accepter molecule excited through irradiation with the second laser light are extracted. Phase lags of the first and second signal components thus extracted are then calculated and the presence of generation of FRET is judged based on these phase lags.

Abstract: A liquid sample flow containing living cells is irradiated with measurement laser light and the photo data of at least either scattering light or fluorescence that is generated by each of the living cells in the liquid sample flow due to the irradiation with the measurement laser light is acquired. Based on the photo data thus acquired, it is determined whether each of the cells assignable to the respective photo data is an unnecessary living cell or a target living cell. Based on the determination results, a pulse voltage is then applied exclusively to the living cells having been determined as unnecessary living cells so that the unnecessary living cells are damaged and killed.

Abstract: A fluroescene detecting device irradiates an object to be measured with a laser beam, receives fluroescene generated from the object and processes a fluorescence signal generated when receiving the fluroescene. The device includes a laser light source section outputting the laser beam for irradiating the object, a light receiving section outputting the fluorescene signal of the fluorescene generated by the irradiated object, a light source control section generates a modulatioon signal having a frequency in order to time-modulate an intensity of the laser beam, and a processing section that calculates a flurescene relaxation time of the fluorescene of the object based on the fluorescene relaxation time of the fluorescene of the object based on the fluorescene relaxation time of the fluorescene of the object based on the fluorescene signal output from the light receiving section.