Method of and system for analizing a sample containing a plurality of fluorescent substances

#The present invention relates to a method of and system for analyzing a sample by simultaneously exciting a plurality of fluorescent substances contained in the sample. The present invention will enable a simultaneous and independent tracing of motions and/or actions of a plurality of proteins or the like contained in a living body, because many proteins and other substances contained in living bodies are naturally fluorescent, or can be fluorescent using fluorescent probes.

#When ultra-short optical pulses of femtosecond (10−15 second) order are spatially converged and irradiated onto a substance, the energy density at the irradiation point becomes so high as to induce linear and nonlinear interactions between the optical pulses and the substance. Various phenomena result from this interaction, one of which is the generation of a pulse of white light with a continuous spectrum (which is referred to as the “continuous spectrum white light pulse” hereinafter). The continuous spectrum white light pulse has a continuous spectrum while being an ultra-short pulse similar to the original pulse. Having such characteristics, the continuous spectrum white light pulse is expected to have various applications.

#An example of several possible applications is the generation of modulation pulse for the transmission of information (Jonathan P. Heritage, Andrew M. Weiner, “Shaping Optical Pulses by Amplitude and Phase Masking”, U.S. Pat. No. 4,655,547, Apr. 7, 1987, Andrew M. Weiner, “Research Projects—Femtosecond Pulse Shaping and Processing”, http://purcell. ecn.purdue.edu/˜fsoptics/PulseShaping.html). As shown in FIG. 1, the continuous spectrum white light 11 generated from an ultra-short optical pulse is dispersed by a dispersing element 12, and the dispersed light passes through a mask 13 having different transmittances or phase shifters for different wavelength components. Then, a lens and a dispersing element 14 combine the light from the mask 13 into one pulse. Thus, a pulse 15 having a Fourier transformation pattern of the mask 13 is obtained.

#FIG. 1 shows the construction of a Fourier transformation system by Weiner.

#FIG. 2 shows the construction of an optical system for generating composite optical pulses for the analysis of a plurality of fluorescent substances according to the present invention.

#FIG. 3 shows the construction of an example of an optical pulse generating system for generating a composite optical pulse in which components of light are separated.

#FIG. 6 shows a fluorescent substance analyzer as an embodiment of the first mode of the present invention. In FIG. 12, the light source 111 is, for example, an erbium-doped fiber laser, a mode-locked Ti:Sapphire laser or a mode-locked Cr:Forsterite laser, which generates an ultra-short optical pulse. The ultra-short optical pulse is converged by a first optical system 112 on a point in a transparent substance 113, such as water or quartz crystal. At the convergence point, a non-linear interaction occurs between the substance 113 and the ultra-short optical pulse, generating a continuous spectrum white light pulse. The continuous spectrum white light pulse enters a second optical system 114 including lenses, reflecting mirrors, etc. The second optical system 114 irradiates the light pulse onto a dispersing element 115, which in turn disperses the light pulse into a spectrum of light. The dispersed light enters a collimator 116, which sends the light to a wavelength selection device 117.

#FIG. 6 shows two types of wavelength selection devices: the first type 117a includes small reflecting mirrors placed on the light paths of the objective wavelengths, and the second type 117b includes a reflecting mirror provided with light-absorbing parts at positions corresponding to wavelength components other than the objective ones.

#Shutters 121 are placed between the collimator 116 and the wavelength selection device 117. As shown in FIG. 7, the shutter 121 includes a rotary shutter unit 122 placed in front of the small reflecting mirror of the wavelength selection device 117a or in front of the reflecting part of the wavelength selection device 117b. Each rotary shutter unit can be arbitrary rotated by key operations on the operation unit 123 provided within easy reach of the user. A rotation of the rotary shutter switches the passing or stopping of light traveling along the light path corresponding to the rotary shutter. The operation unit 123 may be constructed with simple switches. Otherwise, a controller (often a personal computer) for controlling the general operation of the fluorescent substance analyzer may be made to function as the operation unit 123.