JP6166096B2 - Light measuring method and apparatus - Google Patents

Description

  The present invention relates to a light measurement method and apparatus for measuring a light emission amount generated by a light emission reaction of a reagent mixed with a sample with a photodetector, and particularly to correction of a measurement value according to an external environment.

  Since animals, plants, microorganisms (bacteria), etc. always contain adenosine triphosphate (ATP), it has traditionally been used to measure samples such as food stains and microorganisms left on cooking utensils. It is known to estimate the ATP concentration by measuring the light emission amount (RLU) of a minute amount of light generated by the luminescence reaction when a sample is added to a reagent containing luciferase and luciferin in a measurement container with a photodetector. It has been.

  The reagent utilizes an enzyme reaction, and the reaction rate varies depending on the temperature of the reagent. On the other hand, the reagent is stored in a cold place generally in a refrigerated state due to a stability problem. In some cases, the measuring container containing the reagent is stored in a cold place. When the ambient temperature of the place where the apparatus is installed is high, the measured value may change due to a change in reagent temperature. As a conventional device that suppresses the influence of this temperature fluctuation, the amount of light received (the amount of luminescence) generated by the luminescence reaction of the reagent added with the sample in the reaction cell (measuring vessel) inside the analytical tool is measured with a light receiving element. Analyzing equipment that analyzes the component of the sample, arranges an infrared sensor outside the analysis tool so as to receive infrared rays emitted from the reaction cell, and outputs a signal corresponding to the amount of received infrared rays. Known (for example, Patent Document 1). In this apparatus, the measurement result of the amount of received light is corrected according to the surface temperature of the reaction cell.

JP 2011-43520 A

  By the way, the reagent used in the optical measurement device is stored in a cold place as described above, and the measurement is performed by storing the refrigerated reagent according to the ambient temperature and humidity outside the device at the time of measurement. Condensation may occur on the surface of the container. In this case, since the amount of light emission attenuates due to dew condensation on the surface, Patent Document 1 has a problem that the measured value is inaccurate.

  An object of the present invention is to provide a light measurement method and apparatus that can accurately measure the amount of light emitted by the luminescence reaction of a reagent mixed with a sample according to the external environment.

  In order to achieve the above object, a light measurement method according to one configuration of the present invention is a measurement container in which at least a reagent is stored in a cold place and a luminescence reaction is performed by mixing the reagent with a sample in the container. Is a light measuring method in which a light detector is provided in the vicinity of the holding part, each part is housed in a portable main body, and the light emission amount generated by the light emission reaction is measured by the light detector. The amount of light emission is corrected according to the changing surface temperature of the measuring container held in the holding unit, and the holding temperature is adjusted to the surface of the measuring container by the ambient temperature and humidity of the main body. When condensation occurs, the attenuation amount of the light emission amount is corrected according to the condensation amount calculated based on the surface temperature of the measurement container, the ambient temperature of the main body, and the humidity. Here, storing at least a reagent in a cold place means that only the reagent or both the reagent and the measurement container are stored in a refrigerated state.

  An optical measurement device according to another configuration of the present invention holds at least a reagent in a cold place, a measurement container that causes a luminescence reaction by mixing the reagent with a sample in the container, and the measurement container And a control unit that measures the amount of light emitted by the light emission reaction by the light detector, and each part is housed in a main body. A portable light measurement device, wherein the control unit corrects a change in the light emission amount according to a surface temperature of the measurement container held in the holding unit, and a surrounding area of the main body. When dew condensation occurs on the surface of the measurement container in the holding state due to temperature and humidity, the light emission amount depends on the dew amount calculated based on the surface temperature of the measurement container, the ambient temperature of the main body, and the humidity. To correct the attenuation of And a correction means.

  According to this configuration, it has a portable main body, can be used in various external environments, and the amount of light emitted by the luminescence reaction according to the changing surface temperature of the measurement container in the holding state. The amount of light emission is attenuated according to the amount of condensation calculated based on the surface temperature of the measurement container, the ambient temperature of the main body, and the humidity. Can be accurately measured according to the external environment at the time of measurement.

  Preferably, a part of the measurement container is formed of a material having high thermal conductivity. In this case, the reagent temperature and the surface temperature of the measurement container are almost the same, and the reagent temperature can be accurately transmitted as the surface temperature of the measurement container.

  An optical measurement device according to still another configuration of the present invention includes at least a reagent stored in a cold place and mixing the reagent with a sample in the container to cause a luminescence reaction, and the measurement container A holding unit for holding, a photodetector provided in the vicinity of the holding unit, a protective container disposed between the measurement container and the photodetector to protect the inside of the apparatus from the external environment, and a photodetector And a control unit that measures the amount of light emitted by the luminescence reaction, and is a portable light measurement device that houses each part in a main body, the control unit depending on the degree of contamination of the surface of the protective container And a dirt correction means for correcting the attenuation amount of the light emission amount. According to this configuration, the attenuation amount of the light emission amount is corrected in accordance with the degree of contamination of the protective container caused by the external environment. Can be measured accurately.

  The present invention corrects the change in the amount of light emission caused by the luminescence reaction of the reagent mixed in the sample according to the surface temperature of the measurement container, and adjusts the surface temperature of the measurement container, the ambient temperature of the photodetector, and the humidity. Since the attenuation amount of the light emission amount is corrected according to the amount of condensation calculated based on this, when measuring the light emission amount, it can be accurately measured according to the external environment.

It is a schematic block diagram which shows the optical measurement apparatus concerning 1st Embodiment of this invention. It is a characteristic view which shows the dew point generation | occurrence | production on the surface of the measurement container memorize | stored in the optical measurement apparatus of FIG. It is a characteristic view showing the relationship between the surface temperature and the amount of received light. It is a characteristic view which shows the relationship between the stain | pollution | contamination in the surface of the measurement container used with the optical measurement apparatus concerning 2nd Embodiment, and light reception amount.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an optical measurement device 1 according to the first embodiment of the present invention. As shown in the figure, the apparatus 1 includes a mechanism part A and a circuit part B accommodated in a main body 21, and measures a light emission amount of a small amount of light generated by a light emission reaction of a reagent R to which a sample is added. To do. Unlike the conventional installation type, the main body 21 is portable and can be used, and the apparatus 1 can be used under various external environments.

  The measurement mechanism unit A includes, for example, a resin-made measurement container 2 that houses a trace amount of sample S and a reagent R that reacts with the sample S to emit light, a holding unit 3 for holding the measurement container 2, and a holding unit. 3, a lid 4 that opens and closes and shields the holding unit 3 by closing, and a light detector such as a photodiode (PD) that is provided in the vicinity of the holding unit 3 and detects light generated from the sample S. And a shutter 6 that is provided between the measurement container 2 and the light detector 5 and that opens the light detector 5 by switching between opening and closing and shields the light detector 5 by closing. In the lower holding part 3, it is arranged between the measurement container 2 and the shutter 6, that is, between the measurement container 2 and the photodetector 5, and protects the inside of the apparatus from the external environment like a measurement window, for example, A protective container 20 made of a transparent material having a U-shape when viewed from the side is provided.

  The measurement mechanism section A includes a temperature sensor 17 that measures the surface temperature of the measurement container 2, a temperature sensor 18 that measures the ambient temperature of the main body 21, and a humidity sensor 19 that measures humidity. As the temperature sensor 17, an infrared sensor, for example, a thermopile infrared sensor is used. A part of the measurement container 2 facing the temperature sensor 17 is formed of a material having a high thermal conductivity such as an aluminum material. In this case, the reagent temperature and the surface temperature of the measurement container 2 are substantially the same, and the reagent temperature can be accurately transmitted as the surface temperature of the measurement container 2.

  The mechanism part B has a light shielding structure that totally shields external light other than the light from the sample S in the holding part 3. The reagent R is stored, for example, in a refrigerated and light-shielded cool and dark place, and is taken out from the stored state at the time of measurement. In this case, the reagent R may be stored in the measurement container 2 in advance and both the reagent R and the measurement container 2 may be stored in a cool and dark place, or only the reagent R may be stored in a cool and dark place and the reagent R may be stored. May be stored in the measurement container 2 in a room temperature state at the time of measurement.

  The photodetector 5 may use a photomultiplier tube (PMT) that detects by amplifying the current that generates the received light amount in addition to the photodiode (PD) that detects the current that generates the received light amount. . For example, the shutter 6 moves the light shielding plate 22 by an actuator (not shown) to switch between an open state (broken line portion) and a closed state (solid line portion), and exposes or shields the light detector 5.

  In this example, in the present apparatus 1, a shutter 6 is disposed above the photodetector 5, and the holding unit 3 is disposed above the shutter 6. You may make it arrange | position the photodetector 5. FIG.

  Further, the circuit unit B controls the amplifier 11 for amplifying the detection signal from the photodetector 5, the A / D converter 12 for A / D converting the detection signal, and the entire apparatus, and exposes the shutter 6 when it is opened. A control unit (CPU) 7 for measuring the light generated from the sample S by the photodetector 5 in a state of being performed, a storage unit 8 for storing data such as measurement values, and a display unit 9 for displaying operation contents and measurement values And an operation unit 10 such as a switch.

  FIG. 2 is a characteristic diagram showing the occurrence of dew point on the surface of the measurement container 2. The storage unit (memory) 8 in FIG. 1 performs measurement according to various set environmental conditions based on the data in FIG. 2 and the surface temperature of the measurement container 2 and the ambient temperature and humidity data of the main body 21. The amount of condensation on the surface of the container 2 is obtained in advance and stored.

  FIG. 3 is a characteristic diagram showing the relationship between the dew point temperature on the surface of the measurement container 2 and the amount of light received by the photodetector 5. Attenuation amount due to dew condensation of received light amount is corrected according to the dew point temperature.

  The control unit 7 in FIG. 1 is based on the output from the light detector 5, a calculation unit 14 that calculates an RLU (relative light emission amount) that is an index of the ATP concentration of the sample S, a temperature correction unit 15, and a dew condensation correction unit. 16.

  The temperature correction unit 15 corrects the change in the light emission amount according to the surface temperature that changes from the refrigerated state of the measurement container 2 held in the holding unit 3. That is, this apparatus is portable and performs measurement under various external environments, and the temperature of the refrigerated measurement container 2 and the reagent changes according to the ambient temperature of the main body 21. If it does so, the reaction rate of a reagent will change according to the temperature change of a reagent, and the measured value of luminescence will also change. The temperature correction means 15 corrects the change in the light emission amount. This temperature correction is performed using a well-known means such as disclosed in JP-A-2002-202254, for example.

  Further, depending on the ambient temperature and humidity of the main body 21, dew condensation may occur on the surface of the refrigerated measurement container 2 held by the holding unit 3. In this case, the dew condensation correction means 16 corrects the attenuation amount of the light emission amount according to the dew amount calculated based on the surface temperature of the measurement container 2, the ambient temperature of the main body 21, and the humidity.

  The dew condensation correction means 16 first obtains the dew point at which dew condensation occurs on the surface of the measurement container 2 based on the data in FIG. The illustrated α illustrates that the dew point temperature at an ambient temperature of 20 ° C. and a relative humidity of 60% is 12 ° C. As shown in the figure β, for example, when the surface temperature of the measurement container 2 is 5 ° C. and the relative humidity is 80%, this can become the dew point temperature when the ambient temperature is 8 ° C. The temperature difference between the temperatures is 3 ° C., and when the dew point temperature is low and the relative humidity is high, the temperature difference at which condensation occurs is small. Based on the data in FIG. 2 and data on the surface temperature of the measurement container 2 and the ambient temperature and humidity of the main body 21, the amount of condensation on the surface of the measurement container 2 is obtained in advance and stored in the storage unit (memory) 8. ing. The amount of dew condensation increases as the temperature difference between the surface temperature of the measuring container 2 and the ambient temperature increases and as the relative humidity increases.

  Based on the data in FIG. 3, the attenuation amount due to condensation of the received light amount received by the photodetector 5 is corrected according to the dew point temperature of the measurement container 2. As the dew point temperature decreases, the difference from the ambient temperature increases, and the amount of condensation in the measurement container 2 increases, and the amount of correction for the attenuation due to condensation increases.

A light measurement method in the light measurement apparatus having the above configuration will be described.
First, dirt or the like to be inspected is collected as a sample using, for example, a cotton swab, and added (mixed) in the measurement container 2 to the reagent R containing luciferase and luciferin stored in a cool dark place. The measurement container 2 containing the sample and the added reagent R is held by the holding unit 3 with the lid 4 opened. As shown in FIG. 1, the lid 4 is closed while the measurement container 2 is held by the holding unit 3, and the light detector 5 is shielded by closing the shutter 6. Measurement is started by operating the operation unit 10.

  Next, measurement of the sample S is started in a state where the shutter 6 is opened and the photodetector 5 is exposed. Based on the output from the photodetector 5, the light emission amount generated by the light emission reaction of the reagent R added to the sample is calculated by the calculation means 14 as an RLU (relative light emission amount) serving as an index of the ATP concentration. At this time, the amount of light emission change is corrected according to the surface temperature of the measurement container 2 in the refrigerated state, and the amount of condensation calculated based on the surface temperature of the measurement container 2, the ambient temperature of the main body 21, and the humidity Accordingly, the attenuation amount of the light emission amount is corrected, and the corrected RLU (relative light emission amount) is stored in the storage unit 8 and displayed on the display unit 9.

  Thus, the present invention has the portable main body 21 and can be used in various external environments, and the amount of light emitted by the luminescence reaction according to the surface temperature of the refrigerated measurement container 2. The amount of light emission is attenuated in accordance with the amount of condensation calculated based on the surface temperature of the measurement container 2, the ambient temperature of the main body 21, and the humidity. The amount of emitted light can be accurately measured according to the external environment at the time of measurement.

  In the above embodiment, a part of the measurement container is formed of a material having high thermal conductivity. However, it may not be formed if necessary.

  Next, a second embodiment will be described. In the second embodiment, the control unit 7 in FIG. 1 emits light according to the degree of contamination on the surface of the protective container 20 such as the measurement window described above, instead of the temperature correction unit 15 and the condensation correction unit 16. Dirt correction means (not shown) for correcting the amount of attenuation is provided. For example, when the LED 23 is turned on using the dirt monitoring LED 23 provided in the holding unit 3, the degree of dirt is the amount of initial light received by the photodetector 5 when the protection container 20 is not dirty, and the protection level. It is detected by the difference from the amount of light received by the photodetector 5 when dirt is attached to the container 20. In this example, the protective container 20 is U-shaped, but it may be flat.

  The contamination of the surface of the protective container 20 is caused by an external environment such as a reagent spilling from the measurement container 2 or dust entering from the outside when the lid 4 is opened. FIG. 4 is a characteristic diagram showing the relationship between the degree of contamination on the surface of the protective container 20 stored in the storage unit (memory) 8 and the amount of received light. As the degree of contamination increases, the correction amount of the attenuation amount from the initial value increases. Other configurations are the same as those of the first embodiment.

  In the second embodiment, the dirt correction means corrects the attenuation amount of the light emission amount in accordance with the degree of contamination of the protective container caused by the external environment. Accurate measurement is possible according to the external environment at the time of measurement.

  In this embodiment, the protective container 20 is provided, but may be omitted as necessary.

1: Light measuring device 2: Measuring container 3: Holding unit 5: Photo detector 7: Control unit (CPU)
14: Calculation means 15: Temperature correction means 16: Condensation correction means 20: Protection container 21: Body R: Reagent

Claims (3)

At least store the reagent in a cold place, hold the measurement container that causes the luminescence reaction by mixing the reagent with the sample in the container by the holding part, provide a photodetector in the vicinity of the holding part, A light measuring method that is housed in a portable main body and measures the amount of light emitted by the light emission reaction by a photodetector,
The amount of light emission is corrected according to the changing surface temperature of the measurement container held in the holding unit, and condensation occurs on the surface of the measurement container in the held state due to the ambient temperature and humidity of the main body. In this case, the light measurement method corrects the attenuation amount of the light emission amount according to the dew amount calculated based on the surface temperature of the measurement container, the ambient temperature of the main body and the humidity. At least a reagent is stored in a cold place, and a measurement container that causes a luminescence reaction by mixing the reagent with the sample in the container, a holding part for holding the measurement container, and a part near the holding part A portable light measuring device comprising a light detector and a control unit for measuring the amount of light emitted by the light emission reaction by the light detector, and storing each part in the main body,
The controller is
Temperature correction means for correcting the amount of change in the amount of luminescence according to the changing surface temperature of the measurement container held in the holding unit;
When condensation occurs on the surface of the measurement container in the holding state due to the ambient temperature and humidity of the main body, depending on the condensation amount calculated based on the surface temperature of the measurement container, the ambient temperature and humidity of the main body A light measurement apparatus comprising: a dew condensation correcting unit that corrects the attenuation amount of the light emission amount. In claim 2,
The measuring container is a light measuring device, part of which is formed of a material having high thermal conductivity.

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