JP6011367B2 - Fluorometer and sample container for fluorimeter - Google Patents

Description

  The present invention relates to a fluorometer.

As one field of light measurement, a fluorescence measurement technique for measuring fluorescence emitted from a substance is known. Material analysis by fluorescence measurement (fluorescence analysis method) is characterized by high sensitivity and high selectivity compared to absorptiometry and the like, and is effective when performing identification or quantification of a sample.
Sample identification and quantification by fluorescence measurement is limited to the case where the target substance is a fluorescent substance. However, in recent years, fluorescent labeling methods for labeling target substances with reagents (fluorescent reagents) made of fluorescent dyes have been developed, and fluorescent reagents are commercially available for various substances. For this reason, various target substances can be identified and quantified by fluorescence measurement, and their application in many fields such as research and development of new drugs and new materials, process monitoring in plants, and environmental evaluation are being studied. .

  In such fluorescence measurement, the measurement may be performed a plurality of times, and the ratio of the measurement value (fluorescence intensity) in each measurement may be used as a measurement result. For example, Patent Document 1 discloses a technique for identifying and quantifying a sample by fluorescence measurement using an immune reaction. This technology uses the fact that quenching (fluorescence quenching) that has occurred in fluorescent dyes is eliminated by an immune reaction, and is a technology for identifying and quantifying samples using the increase in fluorescence intensity before and after the reaction as an index. is there.

Japanese Patent Laid-Open No. 10-19892

As the application field of fluorescence measurement expands in this way, fluorescence measurement is not performed in a special room such as a laboratory or a measurement room, but is performed in various other places, or samples are collected on-site. It is expected that there will be a need to measure quickly and obtain results quickly. For example, methamphetamine disclosed in Patent Document 1 described above is a typical stimulant and is a so-called prohibited drug. Therefore, the detection of methamphetamine can be performed, for example, by baggage inspection at an airport customs office or by drug enforcement by the police.
Although the activities of so-called drug dogs are widely known for banned drug control at customs, there is a limit to inspecting a large amount of baggage without fail, and even if a substance suspected to be a banned drug is found, To detect and take legal action automatically, the discovered material must be scientifically analyzed and identified. For this purpose, it is necessary to temporarily hold the baggage and take measures such as sending the discovered substance to the inspection organization, and the customs clearance is temporarily put on hold. If a discovered substance can be identified promptly at the site where prohibited drugs are controlled, there is no need to temporarily hold customs clearance and leave travelers for a long time, and they can be caught and arrested immediately. Therefore, there is a need for a practical fluorometer that can be used on-site.

However, a practical fluorometer capable of such on-site measurement has not been developed. Further, it does not teach what point is a problem in a fluorometer capable of on-site measurement.
Considering the on-site fluorescence measurement, the measurement environment becomes a problem. When fluorescence measurement is performed in a special facility such as a laboratory or a measurement room, it is possible to prevent a decrease in measurement accuracy by performing measurement in a clean environment. However, in on-site measurement, it is unavoidable to measure in an environment where there is dust or other foreign matters such as dust (hereinafter collectively referred to as dust), and the measurement accuracy decreases due to dust entering the photometer. It can happen.

  However, when the ratio of two measurement values is taken as a measurement result as in the above-mentioned Patent Document 1, the intrusion of dust is rarely directly connected to a decrease in measurement accuracy. Intruder dust adheres to the elements of the optical system and shields the light, lowering the excitation light from its original intensity, or by blocking the generated fluorescence with dust, the fluorescence is the original intensity detector It may be impossible to capture. Even in such a case, two measurements are performed continuously (or with a shorter time interval), one measurement value is used as reference data, and the ratio of the other measurement value to one measurement value is measured. If this is the case, the measurement accuracy will not decrease.

  However, according to the research of the inventor, it has been found that in fluorescence measurement, there is noise that cannot be removed simply by taking a ratio, and some of the noise is due to circumstances specific to fluorescence measurement derived from dust. . The invention of the present application is based on this finding, and has been made to solve the problem of noise peculiar to fluorescence measurement that cannot be removed only by taking a ratio of measured values.

In order to solve the above problems, the invention according to claim 1 of the present application is a fluorometer for measuring the intensity of fluorescence generated by a sample,
A container holding unit for holding a sample container in which a sample is charged;
A light source for irradiating the sample in the sample container held by the container holder with excitation light;
A detector that captures fluorescence from a sample excited by irradiation of excitation light;
An optical system that guides excitation light from the light source to the sample and guides fluorescence from the sample to the detector;
A container holding part, a light source, a detector and a casing in which an optical system is arranged, and
In the casing, an opening for mounting the sample container to the container holding part is formed,
The casing is provided with a concave dust trap in which dust that has entered the casing through the opening is accumulated, and the dust trap is arranged at a position that cannot be seen from the detector.
In order to solve the above-mentioned problem, the invention according to claim 2 is the configuration according to claim 1, wherein the sample container has an elongated shape, and the container holding portion stores the sample in the sample container. The sample container is held so that the position of the sample container is located on the optical axis of the optical system, and the container holding unit is configured such that the length direction of the sample container is relative to the optical axis of the optical system. Holding the sample container in an intersecting posture;
The dust trap has a configuration in which the dust trap is a part of the container holding portion that is located at a position off the optical path of the optical system.
In order to solve the above problem, the invention according to claim 3 is the configuration according to claim 1 or 2, wherein the dust trap is provided in a state where it can be taken out from the casing. A take-out port for taking out the dust trap is formed.
In order to solve the above problem, the invention according to claim 4 is the configuration of claim 1, 2, or 3, further comprising an arithmetic processing unit for processing the measurement value output from the detector, The arithmetic processing unit has a configuration in which a ratio between two measurement values can be calculated to obtain a measurement result.
In order to solve the above-mentioned problem, the invention according to claim 5 is the structure according to any one of claims 1 to 4, wherein the casing is of a size that can be held by a person and is portable. It has a configuration.
Moreover, in order to solve the said subject, invention of Claim 6 is a sample container used for the fluorometer of the said Claim 2, Comprising: The accommodating part in which a sample is accommodated inside, and the said container Legs that contact the dust trap when held by the holding part are provided, and when the leg comes into contact with the dust trap, the accommodating part is located on the optical axis and is separated from the dust trap. It has the structure of having the length located in the separated position.

As described below, according to the invention described in claim 1 of the present application, there is provided a concave dust trap in which dust that has entered the casing through the opening is provided, and the dust trap cannot be seen from the detector. Since it is arranged, even when the sample container is inserted and removed in an environment where a considerable amount of dust is present, fluorescence measurement can be performed without causing a decrease in accuracy.
According to the invention of claim 2 or 6, in addition to the above effect, the dust trap is a part of the container holding part located at a position off the optical path of the optical system. Excitation light from the light source is not directly irradiated, and dust does not become a noise generation source. For this reason, fluorescence measurement with higher accuracy can be performed.
According to the invention described in claim 3, in addition to the above effects, the dust trap can be removed from the casing, so that dust can be removed before a large amount of dust trap accumulates and a problem (such as dust rising) occurs. Can do.
According to the invention of claim 4, in addition to the above effect, the ratio of two measurement values can be calculated to obtain a measurement result. This is suitable for quantification and the like.
Further, according to the invention described in claim 5, in addition to the above effects, since it is a portable type, it is suitable when performing fluorescence measurement at or near the site where the sample is collected.

1 is a schematic perspective view of a fluorometer according to a first embodiment of the present invention. FIG. 2 is a schematic front sectional view of the fluorometer shown in FIG. 1. It is the schematic of the sample container for fluorometers of embodiment, (1) is an external appearance schematic, (2) is a front cross-sectional schematic. It is a figure which shows the result of the experiment which confirmed that the measurement precision fall by dust penetration | invasion cannot be removed only by taking the ratio of a measured value. It is a front cross-sectional schematic of the fluorometer of 2nd embodiment.

Hereinafter, modes (embodiments) for carrying out the present invention will be described.
FIG. 1 is a schematic perspective view of a fluorometer according to a first embodiment of the present invention. FIG. 2 is a schematic front sectional view of the fluorometer shown in FIG.
The fluorometer shown in FIGS. 1 and 2 is not always installed in a special room such as a measurement room or a laboratory, but is a portable fluorometer. Further, this fluorometer measures the intensity of fluorescence generated in a liquid phase sample (hereinafter referred to as a liquid phase sample), and is a container (hereinafter referred to as a sample container) for holding the liquid phase sample at a measurement position. ) To measure.

More specifically, as shown in FIG. 1, the fluorometer is a flat, substantially rectangular parallelepiped box-like thing as a whole. Since it is portable, its size is about the size of a person's palm or slightly larger.
An opening 11 is formed on the upper surface of the flat, substantially rectangular parallelepiped box-shaped casing 1, and an opening / closing lid 12 is provided in the opening 11. A container holding part 5 is provided in the casing 1, and when the opening / closing lid 12 is opened, the insertion hole 50 at the upper end of the container holder 5 is exposed. A sample container (not shown) in FIG. 1 is inserted into the container holder 5 through the insertion hole 50 and held in the container holder 5 so that the sample container is mounted at a predetermined position in the casing 1. In addition, the front surface of the casing 1 is provided with a display 13 for displaying information necessary for measurement and measurement results, various operation buttons 141 to 146 including a measurement button 141, and the like.

As shown in FIG. 2, in the casing 1, a light source 2 that emits light (excitation light) having a wavelength capable of exciting a sample and emitting fluorescence, a detector 3 that captures the generated fluorescence, and excitation An optical system 4 that guides light to the sample and guides the generated fluorescence to the detector 3, a container holding unit 5 that holds the sample container 8 so that the sample is positioned at the excitation light irradiation position (measurement position), and the like are provided. ing.
Drawing 3 is a schematic diagram of the sample container for fluorometers of an embodiment, (1) is an outline schematic diagram, and (2) is a front section schematic diagram. The sample container shown in FIG. 3 is a container used for the fluorometer shown in FIGS. 1 and 2.

  Although the sample itself may be in a liquid phase, it is assumed that the sample is in a solid state such as a powder, and the generated fluorescence is measured after dissolving in a solution and making it into a liquid phase. It has become. For this reason, the sample container 8 also serves as a purpose of providing a solution for dissolving the sample. In addition, the fluorometer of this example is for performing fluorescence measurement using an immune reaction, and the sample container 8 contains two solutions in advance.

  Specifically, the sample container 8 has a storage part (hereinafter referred to as a first storage part) 81 positioned at the measurement position and a second storage part 82 different from this. A solution (hereinafter referred to as an antibody solution) 83 in which an antibody is dissolved is previously stored in the first storage portion 81. The second accommodating portion 82 is partitioned by a partition wall 84 that can be broken with respect to the first accommodating portion 81. Here, the sample is dissolved and adjusted to a predetermined concentration and then charged into the antibody solution 83. A solution (hereinafter referred to as an adjustment solution) 85 is stored.

In addition, as shown in FIG. 3, the sample container 8 is elongate. The container holding part 5 is a frame-shaped member that matches the size and shape of the sample container 8. As shown in FIG. 3, the 1st accommodating part 81 is provided in the lower end part of the sample container 8, and the 2nd accommodating part 82 is provided in the middle part. The partition wall 84 serves as the bottom wall of the second accommodating portion 82.
The upper end of the sample container 8 is an opening, and a cap-shaped lid 86 is provided in this opening. When the sample is loaded, the lid 86 is opened. Note that when the sample container 8 is correctly held and attached to the container holding part 5, the first storage part 81 is located at the measurement position.

On the other hand, in the fluorometer shown in FIGS. 1 and 2, an LED lamp is used for the light source 2 provided in the casing 1 in consideration of cost advantage and power saving. For example, one that emits green light having a wavelength of 525 nm and that has an output of about 2 mW is used.
The optical system 4 includes a condenser lens 41 that condenses light from the light source 2, a dichroic mirror 42 for bending the optical path and selecting light, and filters 43 and 44 disposed on the optical path. The The light source 2 is configured to emit light downward, and the dichroic mirror 42 is disposed at an oblique angle of 45 ° below the light source 2. The dichroic mirror 42 reflects light having the excitation light wavelength and transmits light having the fluorescence wavelength to be measured.

  The detector 3 is disposed at a position opposite to the container holding unit 5 with the dichroic mirror 42 interposed therebetween. As the detector 3, for example, a detector that performs photoelectric conversion using a silicon photodiode is used. The detector 3 includes a photoelectric conversion unit (silicon photodiode in this example) that receives fluorescence, an amplifier that amplifies the output signal of the photoelectric conversion unit, an output circuit that outputs a signal of fluorescence intensity based on the amplified signal, and the like. Contains. The output circuit optionally includes a calibration circuit for displaying the light intensity as an absolute value.

  An excitation light filter 43 is disposed between the light source 2 and the dichroic mirror 42, and a fluorescence filter 44 is disposed between the dichroic mirror 42 and the detector 3. When green light of 525 nm is used as excitation light, a filter that transmits light in the wavelength range of about 510 to 545 nm and reflects light in other wavelength ranges is used as the excitation light filter 43. In this case, the fluorescence wavelength to be measured is about 550 to 630 nm, and the filter 44 for fluorescence transmits light in the wavelength range of about 570 to 610 nm and reflects light in other wavelength ranges. The The condenser lens 41 irradiates the liquid phase sample in the accommodating portion 81 with the light from the light source 2 as a thin beam, and collects the fluorescence emitted from the liquid phase sample and makes it incident on the detector 3. is there.

As shown in FIG. 2, each element of the light source 2, the detector 3, and the optical system 4 is integrally held by a housing 7. The casing 7 is formed by joining a pair of left and right ones to form a closed space inside, and holds the light source 2, the detector 3, and the optical system 4 in this space. The casing 7 is integrally formed with resin together with the container holding portion 5. The reason for the closed space is to prevent external light from being mixed with excitation light or fluorescence.
However, the boundary portion of the housing 7 with the container holding portion 5 is a measurement opening 70, and the space in the housing 7 communicates with the space in the container holding portion 5 through the measurement opening 70. ing. In order to irradiate the sample in the sample container 8 with excitation light and capture the generated fluorescence, the measurement opening 70 is required.

  A control unit (not shown) is provided in the control box 6 shown in FIG. The control unit performs control of each unit and signal processing, and includes a processor that executes various programs, a memory for storing data and programs, and the like. The programs include a display program for displaying an operation menu on the display 13 and a measurement program for processing the output from the detector 3 to obtain a measurement result.

  When measurement is performed using such a fluorometer, a predetermined amount of sample is collected, put into the second container 84, and dissolved in the adjustment solution 85. In this state, the sample container 8 is mounted on the container holding unit 5 and the light source 2 is turned on to perform measurement. In this state, the sample is only in the second container 82, and the antibody solution 83 is only in the first container 81 at the measurement position. Therefore, the generated fluorescence is measured by irradiating the antibody solution 83 in a state where the sample is not loaded with excitation light. Thereafter, the partition wall 84 of the sample container 8 is broken using a jig (not shown), the adjustment solution 85 in which the sample is dissolved is put into the antibody solution 82 and mixed, and then the measurement is performed again. . If the sample is an antigen, an immune reaction occurs, quenching is eliminated, and fluorescence generated in the antibody solution 83 is enhanced. Therefore, it is possible to identify whether or not the sample is an antigen by calculating the ratio of the two measurement results (two measurement values). Further, the sample can be quantified by comparing the fluorescence enhancement ratio with predetermined calibration data.

  Note that the program stored in the memory (not shown) includes a program for the measurement. Specifically, a program that displays on the display 13 a display that prompts the user to mount the sample container 8 or displays a display that prompts the user to press the measurement button (button that turns on the light source 2) 141 after the mounting is completed. Another example is a program that stores the measurement results of each time in a memory and calculates the ratio to obtain the measurement results.

Now, in the fluorometer as described above, it is inevitable that dust enters the casing 1 as described above. The intrusion of dust can occur when the opening / closing lid 12 is opened for mounting or removing the sample container 8. That is, dust enters from the insertion hole 50 at the upper end of the container holding part 5, descends in the container holding part 5, and then enters the housing 7 through the measurement opening 70. The dust adheres to the elements of the optical system 4.
The casing 1 may have a vent for cooling the light source 2 and the electronic components in the control box 60. In some cases, dust can also enter from this vent, but it can be considerably prevented by providing a filter in the vent, and even if dust enters from the vent, it is difficult to enter the housing, so the optical system 4 There is little adhesion to the element.

According to the inventor's research, it has been found that when dust enters the casing 1 and adheres to the elements of the optical system 4, an unexpected problem arises in that noise cannot be removed simply by taking the ratio of the measured values. Hereinafter, this point will be described.
A typical noise that cannot be removed simply by taking a ratio of measured values is background noise. For example, in the detector 3, there may be a slight output even though no fluorescence is incident. In addition, there is noise in which stray light existing in the casing 1 whose wavelength and range overlap with each other passes through the fluorescent filter 44 and enters the detector 3. Since these noises are superimposed on the output from the detector 3, their magnitudes can be checked in advance and removed by subtracting them from the measurement results.

  The inventor found that even when applying these noise removal techniques in the study of fluorescence measurements he conducted, fluctuations in measurement results that could not be ignored occurred, and this caused a problem that the measurement accuracy could not be increased. . The inventor conducted further diligent research on the cause of this problem, and it has been found that this is due to the influence of intruding dust in the casing 1, particularly due to dust adhering to the elements of the optical system 4.

Some dust that can enter the casing 1 is a fluorescent substance. For example, lint fragments from clothes and the like often become dust, but lint may be a fluorescent material. This is the case where the fiber is a fluorescent material, dyed with a fluorescent paint, or a detergent containing the fluorescent material remains. In addition, human sebum causes dust, but sebum also contains a fluorescent component.
As described above, the dust, which is a fluorescent material, enters the casing 1 and adheres to the elements of the optical system 4. For example, it adheres to the surface of the condenser lens 41. Noise caused by the excitation light and fluorescence being blocked by the dust can be removed by taking the ratio of measured values as described above. However, when dust is a fluorescent substance and the wavelength of the generated fluorescence overlaps with the measurement wavelength (when passing through the filter for fluorescence 44), the dust-derived fluorescence appears in the output from the detector 3. It will be included.
The noise in the case where the dust adhering to the elements of the optical system 4 is a fluorescent material is the same type as the background noise, and cannot be removed only by taking a ratio. Therefore, it is not possible to prevent this kind of decrease in measurement accuracy simply by taking two measurements and taking the ratio.

  FIG. 4 is a diagram showing a result of an experiment confirming that such a decrease in measurement accuracy due to dust intrusion cannot be eliminated simply by taking a ratio of measured values. In the experiment whose result is shown in FIG. 4, the measurement was performed using the same fluorometer and using a container having the same structure as the sample container 8 described above as a reagent container. Two different fluorescent liquid phase reagents a and b were sequentially accommodated in the first accommodating portion of the reagent container, and the fluorescence intensity was measured for each. Specifically, TAMRA was used as a fluorescent reagent, and a solution obtained by dissolving this in a solution at different concentrations was prepared as a liquid phase reagent. One is 1 nmol / liter (liquid phase reagent a) and the other is 5 nmol / liter (liquid phase reagent b). In practice, TAMRA is dissolved in a PBS solution (phosphate buffered saline solution) to a concentration of 1 nmol / liter (liquid phase reagent a), and this is stored in the first storage portion 81 in an amount of 75 μL. The first measurement was performed. Next, the liquid phase reagent reagent in the first container was left as it was, and 25 μL of TAMRA dissolved in a PBS solution to a concentration of 17 nmol / L was added and mixed. Thereby, the liquid phase reagent b was prepared in the 1st accommodating part, and the 2nd measurement was performed in this state.

In the experiment, in order to grasp the amount of background noise, the light source 2 was turned on with no reagent container mounted, the output of the detector 3 was confirmed, and the value was used as the offset value.
In the experiment, in order to grasp the influence of dust intrusion, dust was intentionally introduced into the casing 1 from the insertion hole 50 and measurement was performed. First, the above-mentioned measurement (measurement with respect to the liquid phase reagents a and b) was performed (first measurement set) in a state where dust was not added. Next, after putting a small amount of dust through the insertion hole 50, two measurements were similarly performed (second measurement set). Furthermore, after adding dust, the measurement was performed twice more in the same manner (third measurement set). Dust was not a special thing, but it was collected by throwing things that are indoors on a daily basis.

In FIG. 4, α is an offset value, A is a measured value for the reagent solution a, and B is a measured value for the reagent solution b. The value obtained by subtracting the offset value from each measured value and the finally obtained fluorescence intensity ratio are shown together.
In the combination of the liquid phase reagents a and b, since the concentration ratio is 5 times, the calculated fluorescence intensity ratio is 5 times. Since the same combination of liquid phase reagents a and b is used in each measurement set, the measurement result (fluorescence intensity ratio) must be about 5 times as well, but as shown in FIG. Is fluctuating unstable. Since each measurement is performed continuously in time, it is difficult to consider fluctuation factors other than the intentional introduction of dust, such as fluctuations in the output of the light source 2. Even if an output fluctuation or the like of the light source 2 occurs between the measurement intervals of each set, since the ratio is taken, there should be no influence. Further, since the amount of dust entering the optical system 4 is different, the background noise fluctuates. However, since it is measured in advance as an offset value and subtracted from the measured value, the influence should be removed, but the fluorescence intensity ratio Is fluctuating.

Interestingly, the offset value increases when dust is added and the amount is increased. If the input dust only acts to shield excitation light and fluorescence, the offset value should not fluctuate. The fact that the offset value is increased by the input of dust is considered to directly indicate that the input dust acts as a fluorescence generation source.
Further, when the first measurement set and the second measurement set are compared, the offset values of the measurement values A and B (the offset subtraction is performed although the second measurement set is larger by about 15.5 mV). The previous measurement value) is smaller in the second measurement set. It is considered that this is because the dust that has entered the optical system 4 serves as a fluorescence generation source, but causes a lot of action to shield excitation light and fluorescence from the reagent.

On the other hand, in the third measurement set, the offset value further increases by about 29.0 mV, and the measurement values A and B are conversely larger than the second measurement set and larger than the first measurement set. This result shows that as a result of much dust adhering to the elements of the optical system 4, the action of the dust itself as a fluorescence generation source is stronger than the action of shielding the fluorescence from the excitation light and the reagent. It is thought that there is.
Thus, when dust enters the casing 1, the measurement result fluctuates unstablely. And it is difficult to measure without the influence of the fluctuation. In consideration of such problems, the fluorometer of the embodiment includes a dust trap 9 in the casing 1.

  Specifically, in this embodiment, the dust trap 9 is provided as a part of the container holding unit 5. As shown in FIG. 2, the container holding part 5 is a site | part long in a perpendicular direction. Therefore, the length direction of the container holding part 5 intersects the optical axis Ax of the optical system 4 extending in the horizontal direction perpendicularly. The container holding portion 5 has a portion extending further downward from the lower surface of the housing 7, and this portion is a dust trap 9 in this embodiment.

As shown in FIG. 2, in the fluorometer of the embodiment, the optical path of the excitation light extends horizontally from the dichroic mirror 42 and passes through the measurement opening 70, and the first accommodation of the sample container 8 in the container holding unit 5. Part 81 is reached. The optical path of the fluorescence generated in the first accommodating portion 81 follows the same path, reaches the dichroic mirror 42, passes through the dichroic mirror 42, and reaches the detector 3.
As shown in FIG. 2, the dust trap 9 is at a position out of such an optical path, and is not visible from the detector 3. The container holding part 5 has a bottomed cylindrical shape, and the bottom part is a dust trap 9. When viewed from the optical path of the optical system 4, the dust trap 9 is a portion protruding downward from the housing 7 and has a concave shape for receiving dust falling from above. Note that the dust trap 9 cannot be seen from the detector 3 when each point of the light receiving area of the detector 3 and each point of the bottom surface of the dust trap 9 are connected by a straight line. It is shielded by the member.

As shown in FIG. 3, the sample container 8 has a pair of left and right legs 87. The leg portion 87 is a portion obtained by extending a part of the peripheral wall of the container downward. When the sample container 8 is correctly attached to the container holding part 5, the lower end of each leg 87 is in contact with the bottom surface of the container holding part 5 (bottom surface of the dust trap 9). That is, in the mounted state, the sample container 8 stands on the dust trap 9 by the leg portion 87.
When the sample container 8 is correctly attached to the container holding unit 5, the optical axis Ax of the optical system 4 passes through the middle between the pair of legs 87 as shown in FIG. It will be in the state which reaches the accommodating part 81 of this. That is, the pair of leg portions 87 does not shield excitation light from the light source 2 and does not shield fluorescence from the liquid phase sample in the first storage portion 81.

  In order to hold the sample container 8 in such a posture, the position in the circumferential direction is important. As shown in FIG. 1, the container holding part 5 has a substantially circular cross-sectional shape, but has a linear part in part. As shown in FIG. 3A, the sample container 8 also has a flat surface portion on a part of the side surface. When the sample container 8 is inserted into the container holding part 5 from the insertion hole 50 while matching the flat surface-like part with the linear section of the container holding part 5, the above posture is achieved. That is, the linear part of the container holding part 5 and the flat surface part of the sample container 8 are parts for such alignment.

  In FIG. 2, it is assumed that dust enters the casing 1 from the opening 11 when the opening / closing lid 12 is opened to mount the sample container 8, for example. The dust falls while floating in the container holding unit 5 and reaches the dust trap 9. The dust trap 9 is a lower end portion of the container holding portion 5 and is a concave portion. Therefore, the dust that has reached the dust trap 9 is difficult to move from there to other places. When the number of times the fluorometer is used, the number of times the sample container 8 is taken out and attached, and the amount of dust entering increases, a considerable amount of dust accumulates in the dust trap 9.

  Since the dust trap 9 is at a position out of the optical path, it is not directly irradiated with the excitation light from the light source 2. Nevertheless, there is a slight amount of light from the light source 2 that has become stray light due to abnormal reflection, abnormal refraction, or the like in the housing 7, and dust accumulated in the dust trap 9 may be irradiated with this stray light. In this case, when the dust is a fluorescent material as described above, fluorescence is generated. Even in this case, since the dust trap 9 is in a position where the detector 3 cannot see through, the fluorescence can be captured by the detector 3 even if the wavelength of the fluorescence generated by the dust can pass through the fluorescence filter 44. There is no. For this reason, the dust in the dust trap 9 does not become a noise generation source. Therefore, even when the sample container 8 is inserted and removed in an environment where a considerable amount of dust is present, the fluorescence measurement can be performed without causing a decrease in accuracy.

Note that the length of the leg 87 is such that the depth of the dust trap 9 is such that the first container 81 is positioned on the optical axis Ax of the optical system 4 when the sample container 8 is mounted on the container holder 5. It is appropriately selected according to the height of the first accommodating portion 81 and the like. The first accommodating portion 81 is in a state of being floated (separated) from the dust trap 9 when the leg portion 87 contacts the bottom surface of the dust trap 9.
Although the leg portion 87 is not provided or the leg portion 87 is short and the bottom surface of the first storage portion 81 enters the dust trap 9 and abuts against the bottom surface, the structure can be implemented. The part 81 needs to occupy at least the optical axis Ax of the optical system. For this reason, if a 1st accommodating part enters in the dust trap 9, there will be a problem that a 1st accommodating part will be enlarged unnecessarily and a liquid phase sample will be inevitably increased. In addition, there is a problem that the dust in the dust trap 9 is likely to adhere to the first accommodating portion 81 or the first accommodating portion 81 soars the dust in the dust trap 9. The leg 87 has the significance of preventing such a problem in advance.

Next, the fluorometer of the second embodiment will be described.
FIG. 5 is a schematic front sectional view of the fluorometer of the second embodiment. The fluorometer of the second embodiment is different from the first embodiment in the structure and arrangement position of the dust trap 9. The dust trap 9 of this embodiment is provided in a state where it can be taken out from the casing 1.
Specifically, the casing 1 is provided with a take-out port separately from the opening 11 that is opened and closed by the opening / closing lid 12. The take-out port is at a position on the extension of the container holding part 5 in the length direction. When the casing 1 is in a vertical posture, the takeout port is located immediately below the opening 11 that is opened and closed by the opening / closing lid 12. As shown in FIG. 5, the length of the container holding part 6 is extended to a position near the takeout port.

In this embodiment, the dust trap 9 is a cap-shaped member that closes the outlet. The dust trap 9 is fitted into the take-out port in a posture in which the concave portion faces the inner side (upper side) of the casing. As can be seen from FIG. 6, the dust trap 9 receives dust that has fallen and floated in the space inside the container holding portion 5. In this embodiment as well, the dust trap 9 is at a position out of the optical path of the optical system 4 and is not visible from the detector 3.
The container holding part 5 has a protrusion 51 at a position slightly below the measurement opening 70. The protrusion extends circumferentially along the inner surface of the container holding part 5. As shown in FIG. 5, the sample container 8 is held on the container holding unit 5 by being placed on the protrusion 51.

Also in this embodiment, even if dust enters the casing 1 from the opening 11 when the opening / closing lid 12 is opened for attaching / detaching the sample container 8, the dust reaches the dust trap 9 and remains in the optical system 4. There is no sticking to the element. For this reason, even if the dust is a fluorescent material, it does not become a source of background noise and does not cause a reduction in measurement accuracy.
Moreover, the dust trap 9 can be removed from the take-out port, and the dust accumulated in the recess can be taken out from the casing 1. For this reason, dust can be removed before a large amount of dust accumulates in the dust trap 9 to cause a problem (such as dust rising).

Further, the second embodiment is not a structure in which the sample container 8 is placed on the dust trap 9. For this reason, even when a considerable amount of dust is accumulated in the dust trap 9, the sample container 8 rarely flies up when the sample container 8 is attached or detached.
The structure in which the container holding unit 5 holds the sample container 8 may be a structure in which a bowl-shaped part is provided at the upper end portion of the sample container 8 and this bowl-shaped part is caught on the edge of the upper end opening of the container holding part 5. good.
In each of the above embodiments, the opening 11 of the casing 1 has a structure that is opened and closed by the opening / closing lid 12. However, the opening / closing lid 12 may be omitted, and a structure in which the sample container also serves as a lid that closes the opening 11 may be used. That is, it is possible to adopt a structure in which a bowl-shaped part conforming to the shape of the opening 11 is provided at the upper end part of the sample container, and the bowl-shaped part closes the opening 11 when the sample container is attached to the container holding part 5.

DESCRIPTION OF SYMBOLS 1 Casing 2 Light source 3 Detector 4 Optical system 5 Container holding part 6 Control box 7 Case 8 Sample container 9 Dust trap

Claims (6)

A fluorometer that measures the intensity of fluorescence generated by a sample,
A container holding unit for holding a sample container in which a sample is charged;
A light source for irradiating the sample in the sample container held by the container holder with excitation light;
A detector that captures fluorescence from a sample excited by irradiation of excitation light;
An optical system that guides excitation light from the light source to the sample and guides fluorescence from the sample to the detector;
A container holding part, a light source, a detector and a casing in which an optical system is arranged, and
In the casing, an opening for mounting the sample container to the container holding part is formed,
In the casing, there is provided a concave dust trap in which dust that has entered the casing through the opening is accumulated, and the dust trap is disposed at a position that cannot be seen from the detector. The sample container has an elongated shape, and the container holding unit holds the sample container so that a portion of the sample container containing the sample is positioned on the optical axis of the optical system. The container holder holds the sample container in a posture in which the length direction of the sample container intersects the optical axis of the optical system,
The fluorometer according to claim 1, wherein the dust trap is a portion of the container holding portion that is located at a position off the optical path of the optical system.   The fluorescence intensity according to claim 1 or 2, wherein the dust trap is provided so as to be removable from the casing, and the casing is formed with an extraction port for taking out the dust trap. Total.   An arithmetic processing unit for processing a measurement value output from the detector is provided, and the arithmetic processing unit is capable of calculating a ratio of two measurement values to obtain a measurement result. The fluorometer according to any one of claims 1 to 3.   The fluorometer according to any one of claims 1 to 4, wherein the casing has a size that can be held by a hand and is portable.   A sample container for use in the fluorometer according to claim 2, comprising: a housing part in which a sample is housed; and a leg part that comes into contact with the dust trap when held in the container holding part. The leg portion has a length such that when the abutment comes into contact with the dust trap, the accommodating portion is located on the optical axis and at a position separated from the dust trap. Sample container for fluorometer.

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