Mitsui Engineering and Shipbuilding Company Limited

Hokkaido University

Mitsui Engineering & Shipbuilding

Shigeyuki Nakada

Kazuteru Hoshishima

Hironori Hayashi

Kyouji Doi

Noriaki Kimura

Kenji Yasuda

Takashi Yoshida

Takayoshi Yumii

Yumi Asano

Kyoji Doi

Yusuke Ohba

Akihide Ito

FRET measurement uses a FRET probe that includes a probe element X containing a donor fluorescent substance and a probe element Y containing 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. The modulation frequency of laser light with which the FRET probe is irradiated is adjusted to an optimum modulation frequency that maximizes a difference between the phase difference of donor fluorescence emitted from the donor fluorescent substance with respect to intensity modulation of the laser light at the time when FRET occurs and the phase difference of donor fluorescence emitted from the donor fluorescent substance with respect to intensity modulation of the laser light at the time when FRET does not occur.

FRET measurement device and FRET measurement method

A fluorescence detecting device receives fluorescence emitted by n kinds of measurement objects within wavelength bands FL(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 FL(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 L(k=1) corresponding to at least one of the wavelength bands FLto 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.

Fluorescence detecting device and fluorescence detecting method

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.

Fluorescence measurement device and fluorescence measurement method

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 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 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. After the operation amounts are settled, the detection device calculates the fluorescence intensity and then calculates the fluorescence relaxation time of the fluorescence emitted by the measurement object using the phase delay.

Fluorescence detection device and fluorescence detection method

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.

Flow cytometer having cell-sorting function and method of separating living cells

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.

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.

FRET detection method and device

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.

Fluorescence detecting method and fluorescence detecting device

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.

Fluorescence detection device using intensity-modulated laser light and fluorescence detection method

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.

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.

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.

Growing community of inventors

Tamano, Japan

Shigeyuki Nakada