JP2016185104A - Nucleic acid amplifying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique that increases amplification efficiency of nucleic acid.SOLUTION: A nucleic acid amplifying device 1 comprises: a holding part which holds a reaction vessel 20; a temperature adjusting part which is arranged in a downward vertical direction of the holding part; a heat radiation part 108 which is arranged in a downward vertical direction of the temperature adjusting part; a fan 150 which is arranged in a downward vertical direction of the heat radiation part 108, absorbs air on the heat radiation part 108 side, discharges the air in a downward vertical direction to cool down the heat radiation part 108; and an exhaust duct 200 which is arranged such that an inlet 202 is positioned in a downward vertical direction of the fan 150, and connects the fan 150 to the outside of the device. The exhaust duct 200 makes exhaust air traveling in a downward vertical direction from the fan 150 travel in a horizontal direction and discharges the air from an outlet 204. A portion in the exhaust duct 200 which forms a region 206, where a traveling direction of the exhaust air bends in a horizontal direction from a downward vertical direction, is in a shape that at least one wall surface 206a, 206b inside and outside a curved traveling direction of the exhaust air.SELECTED DRAWING: Figure 1

Description

  The present application relates to a nucleic acid amplification apparatus.

  2. Description of the Related Art Conventionally, nucleic acid amplification apparatuses that amplify nucleic acids by causing a polymerase chain reaction (PCR) to occur in nucleic acids such as DNA (Deoxyribonucleic Acid) are known. In addition, a nucleic acid amplification apparatus that includes a nucleic acid detection unit in addition to a nucleic acid amplification mechanism and can detect amplified nucleic acid in real time is known (for example, see Patent Document 1). Such a nucleic acid amplification device is called a real-time PCR device.

  The real-time PCR apparatus amplifies DNA by controlling the temperature of a reaction sample containing DNA, a fluorescent substance, and the like. The real-time PCR apparatus irradiates excitation light that excites the reaction sample, and measures the amplified DNA based on the fluorescence generated from the reaction sample.

JP 2010-81898 A

  In the nucleic acid amplification apparatus described above, a resin reaction vessel provided with a plurality of depressions for accommodating reaction samples has been used. Further, the reaction vessel is generally placed on a reaction block made of aluminum, and the temperature of the reaction sample is controlled by heating and cooling the reaction block.

  The nucleic acid is amplified by repeating a predetermined temperature cycle. In order to efficiently amplify the nucleic acid, it is desirable to shorten the time required for the temperature of the reaction sample to reach the target temperature in the temperature cycle. As a result of intensive studies, the present inventors have come to recognize that there is room for improving the amplification efficiency of nucleic acids in the conventional diffusion amplification apparatus.

  The present application has been made in view of such circumstances, and an object thereof is to provide a technique for increasing the amplification efficiency of nucleic acids.

  In order to solve the above-described problems, a nucleic acid amplification device according to an aspect of the present application is disposed below a holding unit that holds a reaction vessel in which a plurality of depressions that store reaction samples containing nucleic acids are arranged, and below the holding unit in the vertical direction. A temperature adjusting unit for adjusting the temperature of the reaction sample by heating and cooling the holding unit; a heat dissipating unit for dissipating the temperature adjusting unit; and a heat dissipating unit for dissipating the temperature adjusting unit; The fan that sucks in the air on the side of the heat radiating section and discharges it downward in the vertical direction to cool the heat radiating section, and the exhaust duct that connects the fan and the outside of the device are arranged so that the inlet is positioned below the fan in the vertical direction And comprising. The exhaust duct causes the exhaust gas traveling downward in the vertical direction from the fan to travel in the horizontal direction and exhausts from the outlet, and the portion of the exhaust duct that forms the region where the exhaust traveling direction bends from the vertical bottom to the horizontal direction is the exhaust At least one of the inner and outer wall surfaces in the bending direction has a shape inclined so that the downstream side is closer to the outlet than the upstream side in the exhaust flow direction.

  According to the present application, it is possible to provide a technique for increasing the amplification efficiency of nucleic acid.

1 is a side view schematically showing a nucleic acid amplification apparatus according to an embodiment. 1 is a plan view schematically showing a nucleic acid amplification device according to an embodiment. It is a perspective view which shows typically the reaction unit of the nucleic acid amplifier which concerns on embodiment. It is a disassembled perspective view of the reaction unit of the nucleic acid amplification device according to the embodiment.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The embodiments do not limit the invention but are exemplifications, and all features and combinations described in the embodiments are not necessarily essential to the invention.

  FIG. 1 is a side view schematically showing a nucleic acid amplification apparatus according to an embodiment. FIG. 2 is a plan view schematically showing the nucleic acid amplification device according to the embodiment. In FIG.1 and FIG.2, the state which saw through the inside of the nucleic acid amplifier 1 is shown in figure. A part of the structure is drawn in a sectional view. The nucleic acid amplification device 1 according to the present embodiment controls the temperature of a liquid reaction sample containing a nucleic acid such as DNA and a fluorescent substance to amplify the nucleic acid, and the state of the amplified nucleic acid is measured by an optical measurement method. It is a device that can detect.

  The nucleic acid amplification device 1 includes a main body 15 and a cover 16 attached to the front of the main body 15. In the present embodiment, the main body 15 and the cover 16 are made of resin. The main body 15 is provided with a reaction vessel 20, a cover 22, a reaction unit 100, a control unit 24, a light source 30, a rotation unit 31, filter units 32 and 33, a motor 34, a camera 35, a fan 150, and an exhaust duct 200.

  The cover 16 is installed on the main body 15 so as to be movable back and forth so that the user of the nucleic acid amplification device 1 can replace the reaction container 20. The cover 16 is housed inside the main body 15 when moved backward. FIG. 1 illustrates a state where the cover 16 is moved forward. A light shielding member (not shown) is attached between the main body 15 and the cover 16. Thereby, the internal space of the nucleic acid amplification device 1 is shielded from light. A reflection mirror 25 and a Fresnel lens 26 are installed inside the cover 16.

  In the reaction container 20, a plurality of depressions for storing liquid reaction samples containing nucleic acids and fluorescent substances are arranged. In the present embodiment, a total of 60 depressions are formed in the reaction vessel 20 in the vertical and horizontal equal intervals, 6 vertically and 10 horizontally. In addition, the number of depressions is not particularly limited, and for example, a total of 96 depressions of 8 vertically and 12 horizontally may be formed. The reaction vessel 20 is made of a thin resin plate in order to efficiently transfer the heat of the holding unit described later to the reaction sample. The back side of the reaction vessel 20 has a convex shape corresponding to the depression. In the present embodiment, the nucleic acid in the reaction sample is fluorescently labeled so as to generate two different types of fluorescence L1 and L2 when the fluorescent substance is excited.

  The reaction unit 100 holds the reaction vessel 20 and adjusts the temperature of the reaction vessel 20 based on an instruction from the control unit 24. The reaction unit 100 will be described in detail later.

  The cover 22 is a member that covers the reaction vessel 20. The cover 22 can prevent the reaction sample from evaporating when the reaction vessel 20 is heated. The cover 22 is made of a light-transmitting film or the like so that excitation light for exciting the reaction sample and fluorescence from the reaction sample are transmitted.

  The control unit 24 is realized by an element and a circuit including a CPU and a memory of a computer as a hardware configuration, and is realized by a computer program and the like as a software configuration. The control unit 24 stores various programs and data. The control unit 24 executes each stored program to control each unit of the nucleic acid amplification device 1. For example, the control unit 24 controls the temperature adjustment of the reaction container 20 by the reaction unit 100 so that the nucleic acid is amplified. The control unit 24 controls turning on / off of the light source 30, rotation of the motor 34, and driving of the fan 150. The control unit 24 may be provided outside the main body 15.

  The reflecting mirror 25 reflects the excitation light from the filter units 32 and 33 toward the Fresnel lens 26. The reflecting mirror 25 reflects the fluorescence from the reaction sample toward the camera 35. The Fresnel lens 26 converges and transmits the excitation light reflected by the reflecting mirror 25 in a state parallel to the optical axis of the Fresnel lens 26.

  The light source 30 is installed on the side surface (the side surface on the −Y side) of the main body 15. The light source 30 is a halogen lamp, for example, and irradiates light including excitation light.

  The rotating unit 31 is a so-called turret type rotating device. The rotating unit 31 is equipped with filter units 32 and 33 used when observing fluorescence from the reaction sample. The rotating unit 31 includes rotating plates 60 and 61 and a rotating shaft 62. For example, a maximum of six filter units can be mounted between the rotating plate 60 and the rotating plate 61 in the rotating unit 31.

  The rotating plate 60 is disposed on the camera 35 side. The rotary plate 60 is provided with a round window through which fluorescence passes at a position where the filter parts 32 and 33 are mounted. The rotating plate 61 is disposed on the reflecting mirror 25 side. The rotating plate 61 is provided with a square window that allows excitation light and fluorescence to pass through at positions where the filter portions 32 and 33 are mounted. The rotating shaft 62 rotates the rotating plates 60 and 61 and the filter portions 32 and 33 attached to the rotating plates 60 and 61.

  In the present embodiment, the filter unit 33 is mounted at a position shifted by 180 degrees around the rotation shaft 62 from the position where the filter unit 32 is installed. The rotating unit 31 moves one of the filter units 32 and 33 to a position facing the light source 30 and causes light from the light source 30 to enter the filter unit. The “position facing the light source 30” refers to a position where the optical axis of the light source 30 and the optical filter included in the filter section intersect. In FIG. 2, a state in which the filter unit 32 is in a position facing the light source 30 is illustrated.

  The filter unit 32 is used when observing the fluorescence L1. The filter unit 32 includes a box-shaped filter cube 70, optical filters 71 and 73, and a dichroic mirror 72. The optical filters 71 and 73 and the dichroic mirror 72 are attached to the filter cube 70.

  The optical filter 71 is a band-pass filter that transmits excitation light that excites the reaction sample in the light from the light source 30. The dichroic mirror 72 reflects the excitation light transmitted through the optical filter 71 toward the reflection mirror 25 so as to irradiate the reaction sample with excitation light. The excitation light reflected by the dichroic mirror 72 is further reflected by the reflecting mirror 25, passes through the Fresnel lens 26, and is irradiated on the reaction vessel 20. Further, the dichroic mirror 72 transmits the fluorescence L1 and L2 generated from the excited reaction sample. The optical filter 73 is a band-pass filter that selectively transmits the fluorescence L1 that has passed through the dichroic mirror 72.

  The filter unit 33 is used when observing the fluorescence L2. The filter unit 33 includes a box-shaped filter cube 80, optical filters 81 and 83, and a dichroic mirror 82. The optical filters 81 and 83 and the dichroic mirror 82 are attached to the filter cube 80.

  Similar to the optical filter 71, the optical filter 81 is a bandpass filter that transmits excitation light that excites the reaction sample in the light from the light source 30. The dichroic mirror 82 reflects the excitation light transmitted through the optical filter 81 toward the reflecting mirror 25 and transmits the fluorescence L1 and L2 from the reaction sample. The optical filter 83 is a bandpass filter that selectively transmits the fluorescence L2 that has passed through the dichroic mirror 82.

  The motor 34 rotates the rotating shaft 62 according to an instruction from the control unit 24. The motor 34 is, for example, a stepping motor. The camera 35 receives and captures the fluorescence L1 and L2. As a result, the user of the nucleic acid amplification device 1 can detect the amount of amplified nucleic acid and the like.

  The fan 150 cools a heat radiating part (to be described later) of the reaction unit 100. The exhaust duct 200 connects the fan 150 and the outside of the nucleic acid amplification device 1. The fan 150 and the exhaust duct 200 will be described in detail later.

  Next, the structure and arrangement of the reaction unit 100, the fan 150, and the exhaust duct 200 will be described in detail. FIG. 3 is a perspective view schematically showing the reaction unit 100. FIG. 4 is an exploded perspective view of the reaction unit 100. The reaction unit 100 includes a holding unit 102, a holding unit base 104, a temperature adjusting unit 106, and a heat radiating unit 108 as main components.

  The holding unit 102 is also called a temperature control block or a reaction block, and is a flat plate-like member that holds the reaction vessel 20. One main surface of the holding part 102 is provided with a hole for accommodating the convex part on the back side of the reaction vessel 20. The reaction vessel 20 is placed on one main surface of the holding unit 102. The holding part 102 has thermal conductivity. As a material of the holding portion 102, a metal having high thermal conductivity such as aluminum can be used.

  The holding unit base 104 is a heat insulating member for suppressing heat dissipation from the holding unit 102. The holding unit base 104 is installed on the holding unit 102 via the upper packing 114. The holding unit base 104 has a frame shape and covers the periphery of the holding unit 102. In the central opening of the holding unit base 104, the holding unit 102 is exposed.

  The temperature adjusting unit 106 heats and cools the holding unit 102, thereby adjusting the temperature of the reaction sample in the reaction vessel 20. The temperature adjustment unit 106 is disposed below the holding unit 102 in the vertical direction, and is thermally connected to the holding unit 102 via the heat conducting member 110. The heat conducting member 110 is a member having thermal conductivity such as a silicon sheet, and mediates heat transfer between the holding unit 102 and the temperature adjusting unit 106. The temperature adjustment unit 106 includes a thermoelectric element plate 116 and a substrate 118. The thermoelectric element plate 116 includes a thermoelectric element (not shown) for heating and cooling each of the regions obtained by dividing the holding unit 102 into six equal parts, and a temperature sensor (not shown) for detecting the temperature of the holding unit 102. Have. The thermoelectric element is, for example, a Peltier element. The temperature sensor is, for example, a thermistor.

  A thermoelectric element plate 116 is mounted on the substrate 118. The board 118 has connector-shaped external connection terminals 118a. The control unit 24 and the switching power supply 28 are connected to the external connection terminal 118a. A control signal from the control unit 24 is transmitted to the thermoelectric element plate 116 via the substrate 118, and an output signal of the temperature sensor is transmitted to the control unit 24. The thermoelectric elements of the thermoelectric element plate 116 heat and cool the holding unit 102 based on instructions from the control unit 24. Moreover, the control part 24 controls the heating and cooling by a thermoelectric element based on the output value of a temperature sensor.

  The heat dissipation unit 108 is a member that radiates heat from the temperature adjustment unit 106. Specifically, the heat radiating unit 108 radiates heat from the thermoelectric element of the temperature adjusting unit 106. The heat radiating portion 108 of the present embodiment is a heat sink having a plurality of heat radiating fins 108a. The heat dissipating unit 108 is disposed vertically below the temperature adjusting unit 106 and is connected to the temperature adjusting unit 106 via the lower packing 134 and the heat conducting member 112. The heat conducting member 112 is a member having thermal conductivity such as a silicon sheet, and mediates heat transfer between the temperature adjusting unit 106 and the heat radiating unit 108.

  The holding unit base 104, the holding unit 102, the temperature adjusting unit 106, and the heat radiating unit 108 are fixed by fixing members 136a and 136b.

  The fan 150 is, for example, an axial fan. As shown in FIG. 1, the fan 150 is disposed below the heat radiating unit 108 in the vertical direction, and has a posture that sucks air from the heat radiating unit 108 side and discharges it downward in the vertical direction. When the fan 150 is driven, outside air is taken in through a plurality of slits 15 a provided in the main body 15. The taken-in outside air passes between the plurality of radiating fins 108a, is sucked into the fan 150, and is discharged from the fan 150 downward in the vertical direction. In the process in which the outside air passes between the plurality of heat radiation fins 108a, heat exchange is performed between the heat radiation portion 108 and the outside air. Thereby, the thermal radiation part 108 is cooled. By disposing the fan 150 so that the exhaust direction is downward in the vertical direction, the suction surface or the opening surface of the fan 150 can be made parallel to the main surface of the thermoelectric element plate 116. Thereby, the whole thermal radiation part 108 can be made easy to cool.

  The exhaust duct 200 is disposed so that the inlet 202 is positioned below the fan 150 in the vertical direction. An outlet 204 of the exhaust duct 200 is connected to the outside of the nucleic acid amplification device 1 through a slit 15 b provided in the main body 15. The air heated by heat exchange with the heat dissipating fins 108 a of the heat dissipating part 108 is sucked into the fan 150 and discharged into the exhaust duct 200. The exhaust duct 200 causes the exhaust gas traveling downward in the vertical direction from the fan 150 to travel in the horizontal direction and is discharged from the outlet 204. By providing the exhaust duct 200, the hot air discharged from the fan 150 can be quickly discharged to the outside of the nucleic acid amplification device 1.

  The portion of the exhaust duct 200 that forms the region 206 where the exhaust traveling direction bends in the horizontal direction from below in the vertical direction is such that the wall surface 206a on the outside in the exhaust bending direction is the outlet 204 on the downstream side of the upstream side in the exhaust flow direction. It has a shape that is inclined to approach. Similarly, the inner wall 206b of the exhaust duct 200 in the portion forming the region 206 of the exhaust duct 200 is inclined so that the downstream side is closer to the outlet 204 than the upstream side in the exhaust flow direction. In the present embodiment, the wall surface 206a is a curved surface that expands outward, and the wall surface 206b is a flat surface.

  By inclining the wall surface 206a and the wall surface 206b so that the downstream side of the exhaust flow is closer to the outlet 204 than the upstream side, the exhaust gas flows into the exhaust duct 200 in the region 206 where the traveling direction of the exhaust gas changes from the vertical direction to the horizontal direction. It is possible to suppress noise from colliding with the wall surface.

  The exhaust duct 200 is at least partially formed of a metal plate. In the present embodiment, the wall surface 206b and the upper wall surface 208a of the region 208 where the exhaust gas proceeds in the horizontal direction are formed of a metal plate. The wall surface 206b and the wall surface 208a can be integrally formed.

  The nucleic acid amplification device 1 further includes a switching power supply 28 that supplies a drive voltage to the temperature adjustment unit 106, the control unit 24, the motor 34, the camera 35, and the like. The switching power supply 28 is mounted on the wall surface 208a. Therefore, the switching power supply 28 is thermally connected to the wall surface 208a. The switching power supply 28 is a typical heat source in the nucleic acid amplification device 1. Therefore, the temperature rise in the main body 15 can be efficiently suppressed by thermally connecting the switching power supply 28 to the wall surface 208a formed of a metal plate.

  Next, the operation of the nucleic acid amplification device 1 will be described. Here, as an example, a case where a nucleic acid is amplified using the nucleic acid amplification device 1 and the fluorescence L1 is detected will be described. First, the control unit 24 rotates the rotating unit 31 so that the light from the light source 30 is input to the filter unit 32. Next, the control unit 24 controls the temperature of the thermoelectric element to amplify the nucleic acid in the reaction sample. Thereby, the thermoelectric element repeats heating and cooling of the holding unit 102 in a predetermined temperature cycle. As a result, the heating and cooling of the reaction sample are repeated, and the nucleic acid is amplified.

  Excitation light included in the light emitted from the light source 30 passes through the optical filter 71 and is reflected by the dichroic mirror 72. The reflected excitation light is further reflected by the reflecting mirror 25, passes through the Fresnel lens 26 and the cover 22, and is irradiated on the reaction sample in the reaction vessel 20. As a result, the reaction sample is excited and fluorescence L1 and L2 are generated. The fluorescent lights L 1 and L 2 are reflected by the reflecting mirror 25 and pass through the dichroic mirror 72. The fluorescence L1 and L2 that have passed through the dichroic mirror 72 enter the optical filter 73, and only the fluorescence L1 selectively passes through the optical filter 73 and enters the camera 35. As a result, the camera 35 can detect the fluorescence L1 in real time. Note that the filter unit 33 is used to detect the fluorescence L2.

  As described above, the nucleic acid amplification device 1 according to the present embodiment includes the holding unit 102 that holds the reaction vessel 20 and the temperature adjustment that is disposed below the holding unit 102 in the vertical direction and that heats and cools the holding unit 102. Unit 106, a heat dissipating unit 108 disposed below the temperature adjusting unit 106 in the vertical direction and dissipating heat from the temperature adjusting unit 106, a fan 150 disposed below the heat dissipating unit 108 in the vertical direction, and cooling the heat dissipating unit 108, An inlet 202 is positioned vertically below 150 and includes an exhaust duct 200 that connects the fan 150 and the outside of the nucleic acid amplification device 1.

  Thus, by providing the exhaust duct 200, it is possible to suppress the hot air from staying inside the nucleic acid amplification device 1. Therefore, the heat radiation part 108 can be efficiently cooled. And thereby, in the temperature cycle for amplifying a nucleic acid, the temperature of a reaction sample can be made to reach target temperature earlier. Therefore, nucleic acid amplification efficiency can be improved. Further, by disposing fan 150 such that the exhaust direction is vertically downward, the suction surface of fan 150 can be made parallel to the main surface of thermoelectric element plate 116. Thereby, since the whole thermal radiation part 108 can be cooled, the thermal radiation part 108 can be cooled more efficiently. Accordingly, the nucleic acid amplification efficiency can be further improved.

  Further, the exhaust duct 200 has a structure in which the exhaust gas traveling downward in the vertical direction from the fan 150 travels in the horizontal direction and is discharged from the outlet 204. The wall surfaces 206a and 206b forming the region 206 in the exhaust duct 200 where the exhaust traveling direction bends in the horizontal direction from below in the vertical direction are inclined such that the downstream side in the exhaust flow direction is closer to the outlet 204 than the upstream side. Thereby, when the exhaust gas traveling downward in the vertical direction changes direction in the horizontal direction, it is possible to prevent the exhaust gas from colliding with the wall surface of the exhaust duct 200 and generating noise.

  Further, at least a part of the exhaust duct 200 is formed of a metal plate. Thereby, the heat in the main body 15 can be released to the metal plate. As a result, the heat radiating part 108 can be efficiently cooled, so that the nucleic acid amplification efficiency can be further improved. Further, the switching power supply 28 is thermally connected to the metal plate of the exhaust duct 200. Thereby, the temperature rise in the main body 15 can be efficiently suppressed. As a result, the heat radiating part 108 can be efficiently cooled, so that the nucleic acid amplification efficiency can be further improved.

  The present invention is not limited to the above-described embodiments, and various modifications such as various design changes can be added based on the knowledge of those skilled in the art. Forms are also included within the scope of the present invention. A new embodiment generated by adding a modification to the above-described embodiment has the effects of the combined embodiment and the modification.

  In the embodiment described above, the nucleic acid amplification device 1 includes a nucleic acid amplification mechanism and a detection mechanism. However, the nucleic acid amplification device 1 may include only a nucleic acid amplification mechanism. In the above-described embodiment, both the wall surface 206a and the wall surface 206b are inclined. However, if at least one of the wall surface 206a and the wall surface 206b is inclined, a noise reduction effect can be obtained.

  DESCRIPTION OF SYMBOLS 1 Nucleic acid amplifier, 20 Reaction container, 28 Switching power supply, 102 Holding | maintenance part, 106 Temperature control part, 108 Heat radiation part, 150 Fan, 200 Exhaust duct, 202 Inlet, 204 outlet, 206a, 206b Wall surface

Claims (4)

A holding unit for holding a reaction vessel in which a plurality of recesses for storing reaction samples containing nucleic acids are arranged;
A temperature adjusting unit that is disposed vertically below the holding unit and that heats and cools the holding unit to adjust the temperature of the reaction sample;
A heat dissipating part which is disposed vertically below the temperature adjusting part and dissipates heat from the temperature adjusting part;
A fan that is arranged vertically below the heat dissipating part, sucks in air on the heat dissipating part side, discharges it vertically below, and cools the heat dissipating part,
An exhaust duct which is arranged so that an inlet is located vertically below the fan, and which connects the fan and the outside of the device;
With
The exhaust duct is exhausted from the outlet by causing the exhaust that travels vertically downward from the fan to travel horizontally.
In the exhaust duct, a portion that forms a region in which the exhaust traveling direction bends in the horizontal direction from below in the vertical direction is such that at least one of the inner and outer wall surfaces in the exhaust bending direction is downstream from the upstream side in the exhaust flow direction. A nucleic acid amplification device having a shape that is inclined so that a side approaches the outlet.   The nucleic acid amplification device according to claim 1, wherein at least a part of the exhaust duct is formed of a metal plate. A switching power supply for supplying a driving voltage to the temperature control unit;
The nucleic acid amplification device according to claim 2, wherein the switching power supply is thermally connected to the metal plate.   The nucleic acid amplification device according to any one of claims 1 to 3, wherein the temperature adjustment unit includes a thermoelectric element.