JP2007199458A - Confocal microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a confocal microscope having a function of surely shielding the introduction of exciting light to an optical path during the rotational movement of a filter wheel on a fluorescence observation side. <P>SOLUTION: The confocal microscope is constituted of a microscope unit and a confocal scanner unit, wherein a sample is irradiated with the laser light for excitation of a plurality of wavelengths by changing over the laser light with an excitation side filter means corresponding to each wavelength so as to image the return fluorescent light from the sample to an imaging means via a fluorescence observation side filter means changed over depending on each wavelength of the laser for excitation. The confocal microscope is equipped with a shutter means provided in the middle of the laser light for excitation, and a shutter driving means for shutting off the incidence of the laser light for excitation on the confocal scanner unit by operating the shutter means during the movement period when the fluorescence observation side filter means is changed over. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention comprises a microscope unit and a confocal scanner unit, and switches a plurality of wavelengths of excitation laser light (hereinafter referred to as excitation light) with excitation-side filter means corresponding to each wavelength to irradiate the sample and return from the sample. The present invention relates to a confocal microscope that forms an image on an imaging unit through a fluorescence observation side filter unit that is switched corresponding to each wavelength of the excitation light.

  The details of the Niipou disc type confocal microscope are disclosed in Patent Document 1. FIG. 3 is a functional block diagram illustrating an example of a general system configuration of the confocal microscope. Reference numeral 1 denotes a multi-wavelength excitation light source that emits excitation light. Reference numeral 2 denotes a confocal scanner unit that selectively enters the excitation light from the multi-wavelength excitation light source 1. Reference numeral 3 denotes an inverted microscope unit for fluorescence observation connected to the confocal scanner.

  In the multi-wavelength excitation light source 1, reference numeral 1a denotes an ArKr (argon krypton) gas laser which oscillates simultaneously at wavelengths of 488 nm and 568 nm. These excitation lights are selectively incident on the confocal scanner unit 2 via the optical fiber 4. A semiconductor laser 1b oscillates at a wavelength of 405 nm. This excitation light is incident on the confocal scanner unit 2 via the optical fiber 5.

  Reference numeral 1c denotes an excitation-side filter wheel. The excitation light of the ArKr gas laser 1a is selectively emitted into two wavelengths of 488 nm and 568 nm by an excitation filter that transmits only a specific wavelength mounted on the filter wheel. Is done.

  1d is a shutter provided near the exit of the 405 nm semiconductor laser 1b. When the excitation light of the ArKr gas laser 1a is incident on the confocal scanner unit 2, the shutter is closed and the sample is not irradiated. It is like that.

  When the confocal scanner unit 2 introduces excitation light of 488 nm from the ArKr gas laser 1a, it is possible to excite GFP (green fluorescent protein) or YFP (yellow fluorescent protein), and when introducing 568 nm , DsRed (red fluorescent protein) and mRFP (monomer red fluorescent protein) can be excited. The excitation light is switched by rotating the excitation side filter wheel 1c, and the switching speed is 125 msec at the fastest.

  When the confocal scanner unit 2 introduces excitation light of 405 nm from the semiconductor laser 1b, it is possible to excite DAPI (a kind of fluorescent reagent) or CFP (cyan fluorescent protein).

  As the confocal scanner unit 2, a Niipou plate type unit with a microlens array that suppresses background light is used. This confocal scanner unit incorporates a multiband dichroic mirror that transmits the wavelengths of excitation light, 488 nm and 568 nm, and reflects other wavelengths. Excitation light passes through the pinhole, is irradiated onto the sample via the objective lens, and excites fluorescence on the sample.

  The return fluorescence from the sample passes through the objective lens and again through the pinhole, and is then reflected by the dichroic mirror, and the excitation light is almost attenuated and eliminated by the multiband type barrier filter built in the confocal scanner unit. Is done.

  The return fluorescence is further guided to the fluorescence observation side filter wheel 6. The fluorescence observation side filter wheel 6 is equipped with a spectroscopic optical unit barrier filter manufactured for GFP, YFP, DsRed, mRFP, DAPI, and CFP. Spectral images can be acquired. The switching time of the filter 6 on the fluorescence observation side is also 125 msec at the maximum in synchronization with the excitation side.

  The returned fluorescence that has passed through the fluorescence observation side filter 6 is a high-sensitivity, low-noise HARP camera that forms an imaging means through a zoom lens 7 that expands up to 2.25 times and an image intensifier 8 for light enhancement. 9 and is passed to the control device 11 for capturing an image via the camera controller 10.

  Reference numeral 12 denotes a high-speed sequence processing means composed of TTL (Transistor-Transistor Logic) using bipolar transistors, and is managed by a CPU mounted on the control device 11.

  When acquiring the processing request command C from the control device 11, the sequence processing means 12 performs sequence control of the excitation side filter wheel 1c, the shutter 1d, the fluorescence observation side filter wheel 6, and the camera controller 10 at high speed according to a predetermined sequence.

  FIG. 4 is a functional block diagram showing a filter configuration and its control system mounted on the excitation side and fluorescence observation side filter wheels. The filter wheel 6 on the fluorescence observation side is equipped with bandpass filters f1 to f6 that transmit the fluorescence wavelengths of GFP, YFP, DsRed, mRFP, DAPI, and CFP and block other wavelengths. The fluorescence wavelength to be observed is selected by rotating and moving to (f1 position).

  The fluorescence observation side filter wheel 6 is rotated by an operation signal D1 from the fluorescence observation side filter driving means 13 which is operated by a command from the sequence processing means 12, and moves the predetermined filter on the observation optical path. As the rotation direction, the clockwise direction or the counterclockwise direction is automatically selected so that the distance to the selection target filter is the shortest.

  The excitation-side filter wheel 1c is equipped with a narrow band-pass filter F1 having a center wavelength of 488 nm and a narrow band band-pass filter F2 having a center wavelength of 568 nm. Wavelength switching is performed by alternately changing the positions of these filters on the optical path of the excitation light (F1 position in the drawing).

  When the 405 nmn excitation light of the semiconductor laser 1b is incident, the shielding plate is moved on the excitation light path of the excitation side filter wheel 1c to block the incidence of the 488 nm and 568 nm excitation light, and the shutter 1d is opened. 405 nmn excitation light is incident.

  The excitation-side filter wheel 1c rotates in response to an operation signal D2 from the excitation-side filter driving means 14 that operates in accordance with a command from the sequence processing means 12 in synchronization with the fluorescence observation-side filter wheel 6, and puts the predetermined filter on the optical path of the excitation light. Rotate them alternately. As the rotation direction to the shielding plate, the clockwise direction or the counterclockwise direction is automatically selected so that the distance to the shielding plate is the shortest.

  Reference numeral 15 denotes shutter means provided in the optical path of the excitation light of the excitation side filter wheel 1c. During the period when the excitation light of 488 nm and 568 nm is used, the shutter drive signal S from the excitation side filter drive means 14 is used. It is operated in the open.

  FIG. 5 is a time chart for explaining the processing procedure of the sequence processing means 12. (A) is a frame synchronization signal, (B) is a start signal from the CPU, and (C) is a shutter drive signal.

  This shutter drive signal is generated during the period when the excitation light of 488 nm and 568 nm is used by the filters F1 and F2 by the rotation operation of the excitation side filter wheel as shown in (D), that is, during the period from time t1 to t4. The means 15 is operated to open. Therefore, the shutter means 15 is operated to open even during the movement period from time t2 to time t3 when the filter F1 is switched to F2.

  FIG. 5E shows the rotation operation of the observation-side filter wheel. During the period from time t1 to time t2 when F1 is selected, the filters f1 and f2 are switched to perform 488 nmGFP observation and 488 nmYFP observation, and F2 is selected. In the period from the time t3 to t4, the filter is switched to f4, and 568 nm mRFP observation is executed.

  FIG. 5F is an operation trigger signal for the observation-side filter wheel triggered at the camera exposure end timing shown in FIG. 5H. During the period in which the filter is rotating, the BUSY signal shown in FIG. Is output. (I) is an image transfer trigger signal, which occurs during the exposure time of (H). (J) is an image transfer signal generated at the end of the exposure time of (H).

Japanese Patent Laid-Open No. 5-60980

  Since the 488 nm excitation light of the ArKr gas laser 1a has a side band, the notch type multi-band filter cannot block and there is a slight amount of leakage light. The filters mounted on the fluorescence observation side filter wheel 6 are arranged in the order of f1 to f6, GFP, YFP, DsRed, mRFP, DAPI, and CFP.

  FIG. 6 is an image diagram showing a moving path of the filter that is switched by the fluorescence observation side filter wheel 6 according to the fluorescent protein to be observed. When the fluorescent proteins to be observed are YFP (filter f2) and mRFP (filter f4), as shown in FIG. 6A, the fluorescence observation side filter wheel 6 rotates in the forward direction from YFP → DsRed → mFRP. Since any of YFP, DsRed, and mFRP does not transmit the excitation light near 488 nm, no problem occurs.

  On the other hand, when the fluorescent proteins to be observed are GFP (filter f1) and mRFP (filter f4), the fluorescence observation side filter wheel 6 rotates in the reverse direction of GFP → DAPI → CFP → mRFP. Since the DAPI and CFP filters transmit light around 488 nm due to the characteristics, the image intensifier 8 is irradiated for a short time, but the image is saturated. Thus, a problem occurs depending on the rotation direction of the fluorescence observation side filter wheel 6.

  As described above with reference to FIG. 5, the cause of such a problem is that the excitation-side shutter unit 15 remains open during the rotational movement of the filter by the fluorescence observation-side filter wheel 6. This is because the sample is unnecessarily irradiated with excitation light.

When such a situation occurs, the following inconvenience occurs.
(1) Unnecessary excitation light hits the sample, and the labeled fluorescent material fades.
(2) Since the excitation light is not sufficiently blocked by the fluorescent filter, strong light enters the photocathode of the image intensifier and degrades the image intensifier.

  The present invention has been made to solve the above-described problems, and has a function of reliably blocking the introduction of excitation light into the optical path while the filter wheel on the fluorescence observation side is rotating. The purpose is to realize a confocal microscope.

In order to achieve such a subject, the present invention has the following configuration.
(1) Consisting of a microscope unit and a confocal scanner unit, excitation light having a plurality of wavelengths is switched by excitation-side filter means corresponding to each wavelength and irradiated onto the sample, and the return fluorescence from the sample is used for the excitation. In the confocal microscope that forms an image on the imaging means through the fluorescence observation side filter means that is switched corresponding to each wavelength of the laser,
Shutter means provided in the middle of the excitation laser beam;
During the movement period in which the fluorescence observation side filter means is switched, the shutter means is operated to shut off the incidence of the excitation laser light on the confocal scanner unit; and
A confocal microscope characterized by comprising:

(2) An excitation side filter driving means and a fluorescence observation side filter driving means for operating the excitation side filter means and the fluorescence observation side filter means are provided, and these driving means are provided by a sequence processing means driven by a command of a host CPU. The confocal microscope according to (1), which is controlled.

(3) The confocal microscope according to (1) or (2), wherein the shutter driving unit is controlled by inputting movement information from the sequence processing unit and the fluorescence observation side filter driving unit. .

(4) The moving directions of the excitation side filter means and the fluorescence observation side filter means are controlled according to an algorithm provided by the excitation side filter drive means and the fluorescence observation side filter drive means themselves (2) or The confocal microscope according to (3).

As is apparent from the above description, the present invention has the following effects.
(1) Since unnecessary excitation light is not irradiated on the sample, observation can be performed for a longer time. (2) Since the excitation light is completely shielded by the shutter means, light leaks to the photocathode of the image intensifier. Therefore, the image intensifier does not deteriorate or the image is not saturated.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a functional block diagram showing a filter configuration and its control system mounted on the excitation side and fluorescence observation side filter wheels of a confocal microscope to which the present invention is applied. The same elements as those of the conventional confocal microscope described with reference to FIGS. Hereinafter, the characteristic part of the present invention will be described.

  In FIG. 1, reference numeral 100 denotes a sequence processing means to which the present invention is applied. The basic function is the same as that of the sequence processing means 12 described with reference to FIG. 5, but is characterized by the sequence control form of the shutter means 15 provided in the middle of the excitation light.

  Reference numeral 200 denotes shutter driving means to which the present invention is applied, which obtains a command from the sequence processing means 100 and a rotational movement-in-progress signal M from the fluorescence observation-side filter wheel 13, and the fluorescence observation-side filter wheel 6 is in rotational movement. Operates the shutter means 15 to close.

  FIG. 2 is a time chart for explaining the processing procedure of the sequence processing means 100. The difference from the time chart showing the processing procedure of the conventional sequence processing means 12 described in FIG. 5 is the sequence processing by the shutter driving signal (C).

  In conventional shutter drive signal sequence processing, a period in which excitation light of 488 nm and 568 nm is used in the rotation operation of the excitation side filter wheel, that is, a period from time t1 to t6 (in FIG. 5, a period from t1 to t4). ), The shutter means 15 is operated to open.

  In the sequence processing according to the present invention, during the period from time t1 to t6, the period during which the fluorescence observation side filter wheel shown in (E) is rotationally moved from the filter f1 to the filter f2, that is, the period from time t2 to t3 During the operation, the shutter means 15 is closed as shown in FIG.

  The timing at time t2 is a drive trigger signal for the fluorescence observation side filter wheel shown in (F), and the timing at time t3 is the end time of the BUSY signal of the fluorescence observation side filter wheel shown in (G).

  Similarly, during the period in which the fluorescence observation side filter wheel is rotationally moved from the filter f2 to the filter f4, that is, the period from t4 to t5, the shutter means 15 is operated to close as shown in FIG.

  Similarly, the timing at time t4 is a drive trigger signal for the fluorescence observation side filter wheel shown in (F), and the timing at time t5 is the end time of the BUSY signal of the fluorescence observation side filter wheel shown in (G). .

  In the embodiment described above, the TTL using the bipolar transistor is exemplified as the sequence processing unit 100 that executes the high-speed processing. However, the present invention is not limited to this, and a logic circuit or the like using the CMOS transistor can be adopted. is there.

It is a functional block diagram which shows the filter structure mounted in the excitation side and fluorescence observation side filter wheel of the confocal microscope to which this invention is applied, and its control system. It is a time chart explaining the process sequence of the sequence process means of FIG. It is a functional block diagram which shows an example of the general system configuration | structure of a confocal microscope. It is a functional block diagram which shows the filter structure mounted in the excitation side and the fluorescence observation side filter wheel, and its control system. It is a time chart explaining the process sequence of the sequence processing means of FIG. It is an image figure which shows the movement path | route of the filter switched by the fluorescence observation side filter wheel according to the fluorescent protein to observe.

Explanation of symbols

1c Excitation side filter wheel 6 Fluorescence observation side filter wheel 11 Control device 13 Fluorescence observation side filter driving means 14 Excitation side filter driving means 15 Shutter means 100 Sequence processing means 200 Shutter driving means

Claims (4)

It consists of a microscope unit and a confocal scanner unit, switches excitation laser light of multiple wavelengths with excitation-side filter means corresponding to each wavelength, irradiates the sample, and returns fluorescence from the sample to each wavelength of the excitation laser. In the confocal microscope that forms an image on the imaging means through the fluorescence observation side filter means that is switched corresponding to
Shutter means provided in the middle of the excitation laser beam;
During the movement period in which the fluorescence observation side filter means is switched, the shutter means is operated to shut off the incidence of the excitation laser light on the confocal scanner unit; and
A confocal microscope characterized by comprising:   Excitation side filter drive means and fluorescence observation side filter drive means for operating the excitation side filter means and fluorescence observation side filter means are provided, and these drive means are controlled by sequence processing means driven by commands of a host control device. The confocal microscope according to claim 1.   The confocal microscope according to claim 1, wherein the shutter driving unit is controlled by inputting movement information from the sequence processing unit and the fluorescence observation side filter driving unit. The moving direction of the excitation side filter unit and the fluorescence observation side filter unit is controlled according to an algorithm provided by the excitation side filter drive unit and the fluorescence observation side filter drive unit itself. Confocal microscope.

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