1. Technical Field
The present invention relates to a nucleic acid amplification reaction apparatus.
2. Related Art
As a method of amplifying nucleic acid at high speed, there is known a method of injecting oil and a small amount of nucleic acid amplification reaction liquid into a cylindrical nucleic acid amplification reaction container, maintaining one end of the container at high temperature and maintaining the other end at low temperature, and generating a heat cycle in the temperature of the nucleic acid amplification reaction liquid at high speed by rotating the container to alternately switch a state in which the one end is placed lower in the vertical direction to locate the reaction liquid in the high-temperature oil and a state in which the other end is placed lower in the vertical direction to locate the reaction liquid in the low-temperature oil (see, for example, JP-A-2012-115208 (Patent Literature 1)).
In the method described in Patent Literature 1, when one end of the container maintained at high temperature is directed downward, the high-temperature oil is located on the lower side of the low-temperature oil. At this point, the high-temperature oil rises and the low-temperature oil falls. Therefore, a convection current occurs in the oil in the container and the temperature of the oil at both the ends of the container fluctuates. A nucleic acid amplification reaction is likely to become unstable. As a result, there is possibility that variation occurs in an amplification amount of nucleic acid.
An advantage of some aspects of the invention is to provide a nucleic acid amplification reaction apparatus that can stably amplify nucleic acid.
An aspect of the invention is directed to a nucleic acid amplification reaction apparatus including: a mounting section mountable with a nucleic acid amplification reaction container having a longitudinal direction and filled with reaction liquid and liquid that has specific gravity smaller than the specific gravity of the reaction liquid and does not mix with the reaction liquid; a first heating section configured to heat a first region of the nucleic acid amplification reaction container to a first temperature; a second heating section configured to heat a second region of the nucleic acid amplification reaction container to a second temperature; and a driving mechanism configured to switch the arrangement of the first region and the second region in the order of first arrangement, second arrangement, and third arrangement. The second temperature is higher than the first temperature. The first arrangement and the third arrangement are arrangement in which the first region is below the second region in a direction in which the gravity acts. The second arrangement is arrangement in which the second region is below the first region in the direction in which the gravity acts. The nucleic acid amplification reaction container includes a projecting section where an inner wall of the nucleic acid amplification reaction container projects outward. The projecting section is configured to enable the reaction liquid to stay in the projecting section in the third arrangement. The projecting section may be a step provided on the inner wall and including an inclined surface inclined with respect to or a surface perpendicular to an axis along the longitudinal direction of the nucleic acid amplification reaction container.
Another aspect of the invention is directed to a nucleic acid amplification reaction apparatus including: a nucleic acid amplification reaction container having a longitudinal direction and filled with reaction liquid and liquid that has specific gravity smaller than the specific gravity of the reaction liquid and does not mix with the reaction liquid; a first heating section configured to heat a first region of the nucleic acid amplification reaction container to a first temperature; a second heating section configured to heat a second region of the nucleic acid amplification reaction container to a second temperature; and a driving mechanism configured to switch the arrangement of the first region and the second region in the order of first arrangement, second arrangement, and third arrangement. The second temperature is higher than the first temperature. The first arrangement and the third arrangement are arrangement in which the first region is below the second region in a direction in which the gravity acts. The second arrangement is arrangement in which the second region is below the first region in the direction in which the gravity acts. The nucleic acid amplification reaction container includes a projecting section where an inner wall of the nucleic acid amplification reaction container projects outward. The projecting section is configured to enable the reaction liquid to stay in the projecting section in the third arrangement.
Still another embodiment of the invention is directed to a nucleic acid amplification reaction container having a longitudinal direction and filled with reaction liquid and liquid that has specific gravity smaller than the specific gravity of the reaction liquid and does not mix with the reaction liquid. The nucleic acid amplification reaction container includes a projecting section where an inner wall of the nucleic acid amplification reaction container projects outward. The projecting section is configured to enable the reaction liquid to stay in the projecting section when a first region, which is one end in the longitudinal direction of the nucleic acid amplification reaction container, is arranged below a second region, which is the other end in the longitudinal direction, in a direction in which the gravity acts. The projecting section may be a step provided on the inner wall and including an inclined surface inclined with respect to or a surface perpendicular to an axis along the longitudinal direction of the nucleic acid amplification reaction container.
According to the aspects of the invention, it is possible to provide a nucleic acid amplification reaction apparatus that can stably amplify nucleic acid.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Preferred embodiments of the invention are explained below with reference to the drawings. Note that the embodiments explained below do not unduly limit contents of the invention described in the appended claims. Not all of components explained below are essential constituent elements of the invention.
The nucleic acid amplification reaction apparatus 1 includes, as shown in
The mounting section 11 is a structure on which the nucleic acid amplification reaction container 100 is mounted. As shown in
The nucleic acid amplification reaction apparatus 1 preferably includes a structure that retains the nucleic acid amplification reaction container 100 in a predetermined position with respect to the first heating section 12 and the second heating section 13. Consequently, a predetermined region of the nucleic acid amplification reaction container 100 can be heated by the first heating section 12 and the second heating section 13. More specifically, as shown in
When the nucleic acid amplification reaction container 100 is mounted on the mounting section 11, the first heating section 12 heats the first region 111 of the nucleic acid amplification reaction container 100 to a first temperature. In an example shown in
The first heating section 12 may include a mechanism that generates heat and a member that transmits the generated heat to the nucleic acid amplification reaction container 100. In an example shown in
Since temperature control of the cartridge heater is easy, when the first heater 12a is the cartridge heater, it is possible to easily stabilize the temperature of the first heating section 12. Therefore, it is possible to realize a more accurate heat cycle. Since aluminum has high thermal conductivity, when the first heat block 12b is made of aluminum, it is possible to efficiently heat the nucleic acid amplification reaction container 100. Since heating unevenness less easily occurs in the first heat block 12b, it is possible to realize a highly accurate heat cycle. Since machining is easy, it is possible to accurately mold the first heat block 12b and improve accuracy of the heating. Therefore, it is possible to realize a more accurate heat cycle.
The first heating section 12 is preferably in contact with the nucleic acid amplification reaction container 100 when the nucleic acid amplification reaction container 100 is mounted on the mounting section 11. Consequently, when the nucleic acid amplification reaction container 100 is heated by the first heating section 12, it is possible to stably transmit heat of the first heating section 12 to the nucleic acid amplification reaction container 100. Therefore, it is possible to stabilize the temperature of the nucleic acid amplification reaction container 100. When the mounting section 11 is formed as a part of the first heating section 12, the mounting section 11 is preferably in contact with the nucleic acid amplification reaction container 100. Consequently, it is possible to stably transmit the heat of the first heating section 12 to the nucleic acid amplification reaction container 100. Therefore, it is possible to efficiently heat the nucleic acid amplification reaction container 100.
When the nucleic acid amplification reaction container 100 is mounted on the mounting section 11, the second heating section 13 heats the second region 112 of the nucleic acid amplification reaction container 100 to a second temperature different from the first temperature. In the example shown in
The temperatures of the first heating section 12 and the second heating section 13 are controlled by a temperature sensor and a control section not shown in the figure. The temperatures of the first heating section 12 and the second heating section 13 are preferably set such that the nucleic acid amplification reaction container 100 is heated to desired temperature. By controlling the first heating section 12 to the first temperature and controlling the second heating section 13 to the second temperature, it is possible to heat the first region 111 of the nucleic acid amplification reaction container 100 to the first temperature and heat the second region 112 to the second temperature. The temperature sensor is a thermocouple.
The driving mechanism 20 is a mechanism that drives the mounting section 11, the first heating section 12, and the second heating section 13. The driving mechanism 20 includes a motor and a driving shaft not shown in the figure. The driving shaft and the flanges 16 of the main body 10 are connected. The driving shaft is provided perpendicularly to the longitudinal direction of the mounting section 11. When the motor is operated, the main body 10 is rotated with the driving shaft as an axis of rotation.
The nucleic acid amplification reaction apparatus 1 in this embodiment includes the not-shown control section. The control section controls at least one of the first temperature, the second temperature, a first time, a second time, and the number of cycles of a heat cycle. When the control section controls the first time or the second time, the control section controls the operation of the driving mechanism 20 to thereby control time in which the mounting section 11, the first heating section 12, and the second heating section 13 are retained in predetermined arrangement. The control section may be provided with different mechanisms for respective items to be controlled or may collectively control all the items.
The control section in the nucleic acid amplification reaction apparatus 1 performs electronic control and controls all the items. The control section includes a processor such as a CPU and storage devices such as a ROM (Read Only Memory) and a RAM (Random Access Memory) not shown in the figure. Various computer programs, data, and the like for controlling the items are stored in the storage devices. The storage devices include work areas where data being processed, a processing result, and the like of various kinds of processing are temporarily stored.
In the main body 10, as shown in the examples shown in
The material of the spacer 14 can be selected as appropriate according to necessity. However, the material is preferably a heat insulating material. Consequently, it is possible to reduce the mutual influence of the heat of the first heating section 12 and the second heating section 13. Therefore, it is easy to perform the temperature control of the first heating section 12 and the second heating section 13. If the spacer 14 is the heat insulating material, when the nucleic acid amplification reaction container 100 is mounted on the mounting section 11, the spacer 14 is preferably arranged to surround the nucleic acid amplification reaction container 100 in a region between the first heating section 12 and the second heating section 13. Consequently, it is possible to suppress heat radiation from the region between the first heating section 12 and the second heating section 13 of the nucleic acid amplification reaction container 100. Therefore, the temperature of the nucleic acid amplification reaction container 100 further stabilizes. The spacer 14 is the heat insulating material. In the example shown in
The main body 10 includes the fixing plates 19. The fixing plates 19 are members that retain the mounting section 11, the first heating section 12, and the second heating section 13. In the examples shown in
The nucleic acid amplification reaction apparatus 1 includes the lid 50. In the examples shown in
The main body 10 is preferably a structure having high airtightness. If the main body 10 is the structure having high airtightness, the air inside the main body 10 less easily escapes to the outside of the main body 10. Therefore, the temperature in the main body 10 further stabilizes. As shown in
The fixing plates 19, the bottom plate 17, the lid 50, and the flanges 16 are preferably formed using a heat insulating material. Consequently, it is possible to further suppress the heat radiation from the main body 10 to the outside. Therefore, it is possible to further stabilize the temperature in the main body 10.
As shown in an example shown in
The first region 111 of the nucleic acid amplification reaction container 100 is a region in a part of the channel 110 heated to the first temperature by the first heating section 12. The second region 112 is a region in a part of the channel 110 heated to the second temperature by the second heating section 13 and different from the first region 111. In the nucleic acid amplification reaction container 100, the first region 111 is a region including one end portion in the longitudinal direction of the channel 110. The second region 112 is a region including the other end portion in the longitudinal direction of the channel 110. In the examples shown in
The liquid 130 and the reaction liquid 140 are filled in the channel 110. The liquid 130 does not mix with the reaction liquid 140, that is, does not dissolve in the reaction liquid 140. Therefore, as shown in
The shuttle PCR is a method of repeatedly applying temperature treatment in two stages of high temperature and low temperature to reaction liquid to thereby amplify nucleic acid in the reaction liquid. In the treatment at the high temperature, dissociation of double-stranded DNA is performed. In the treatment at the low temperature, annealing (a reaction in which the primer combines with single-stranded DNA) and an extension reaction (a reaction in which a complementary chain of DNA is formed starting from the primer) are performed.
In general, the high temperature in the shuttle PCR is temperature between 80° C. and 100° C. and the low temperature is temperature between 50° C. and 70° C. In general, the treatment at the temperatures is performed for a predetermined time. Time for retaining the reaction liquid at the high temperature is shorter than time for retaining the reaction liquid at the low temperature. For example, the time for retaining the reaction liquid at the high temperature may be set to approximately one second to ten seconds and the time for retaining the reaction liquid at the low temperature may be set to approximately ten seconds to sixty seconds. Depending on condition of the reaction, the times for retaining the reaction liquid at the high temperature and the low temperature may be longer than these times.
Appropriate times, temperatures, and the number of cycles (the number of times the high temperature and the low temperature are repeated) are different depending on a type and an amount of a reagent in use. Therefore, it is preferable to perform the reaction after determining an appropriate protocol taking into account a type of a reagent and an amount of the reaction liquid 140.
First, the nucleic acid amplification reaction container 100 is mounted on the mounting section 11 (step S101). In this embodiment, after the reaction liquid 140 is introduced into the channel 110 filled with the liquid 130, the nucleic acid amplification reaction container 100 sealed by the sealing section 120 is mounted on the mounting section 11. The introduction of the reaction liquid 140 can be performed using a micro pipet, a dispensing device of an inkjet type, or the like. In a state in which the nucleic acid amplification reaction container 100 is mounted on the mounting section 11, the first heating section 12 and the second heating section 13 are in contact with the nucleic acid amplification reaction container 100 respectively in a position including the first region 111 and a position including the second region 112. In this embodiment, since the nucleic acid amplification reaction container 100 is mounted in contact with the bottom plate 17 as shown in
In this embodiment, the arrangement of the mounting section 11, the first heating section 12, and the second heating section 13 in step S101 is the first arrangement. As shown in
In step S102, the nucleic acid amplification reaction container 100 is heated by the first heating section 12 and the second heating section 13. The first heating section 12 and the second heating section 13 heat different regions of the nucleic acid amplification reaction container 100 to different temperatures. That is, the first heating section 12 heats the first region 111 to the first temperature. The second heating section 13 heats the second region 112 to the second temperature. Consequently, a temperature gradient in which temperature gradually changes between the first temperature and the second temperature is formed between the first region 111 and the second region 112 of the channel 110. In this embodiment, the first temperature is relatively high temperature among temperatures suitable for a target reaction in the heat cycle treatment. The second temperature is relatively low temperature among the temperatures suitable for the target reaction in the heat cycle treatment. Therefore, in steps S102 in this embodiment, a temperature gradient in which temperature decreases from the first region 111 to the second region 112 is formed. The heat cycle treatment in this embodiment is the shuttle PCR. Therefore, it is preferable to set the first temperature to temperature suitable for dissociation of double-stranded DNA and set the second temperature to temperature suitable for annealing and an extension reaction.
In step S102, the arrangement of the mounting section 11, the first heating section 12, and the second heating section 13 is the first arrangement. Therefore, when the nucleic acid amplification reaction container 100 is heated in step S102, the reaction liquid 140 is heated to the first temperature. Therefore, in step S102, the reaction liquid 140 is caused to react at the first temperature.
In step S103, it is determined whether the first time has elapsed in the first arrangement. In this embodiment, the determination is performed by the not-shown control section. The first time is time in which the mounting section 11, the first heating section 12, and the second heating section 13 are retained in the first arrangement. In this embodiment, when step S103 is performed following the mounting in step S101, that is, when step S103 is performed for the first time, it is determined whether time after the nucleic acid amplification reaction apparatus 1 is actuated has reached the first time. In the first arrangement, the reaction liquid 140 is heated to the first temperature. Therefore, the first time is preferably set to time in which the reaction liquid 140 is caused to react at the first temperature in the target reaction. In this embodiment, the first time is preferably set to time necessary for dissociation of double-stranded DNA.
When it is determined in step S103 that the first time has elapsed (YES), the processing proceeds to step S104. When it is determined in step S103 that the first time has not elapsed (NO), step S103 is repeated.
In step S104, the main body 10 is driven by the driving mechanism 20. The arrangement of the mounting section 11, the first heating section 12, and the second heating section 13 is switched from the first arrangement to the second arrangement. Thereafter, the arrangement is switched to the third arrangement. The second arrangement is arrangement in which the axis of the nucleic acid amplification reaction container 100 is parallel to the vertical line (
When it is determined in step S105 that the second time has elapsed (YES), the processing proceeds to step S106. When it is determined in step S105 that the second time has not elapsed (NO), step S105 is repeated.
In this embodiment, in the projection section 150 in the second region 112 of the nucleic acid amplification reaction container 100, there are a portion where the size of a diameter is “a” and a portion where the size of a diameter if “b”. The size “b” of the diameter on the lower part 112b side is smaller than the size “a” of the diameter on the upper part 112a side, and the diameter of the second region decreases toward the lower part 112b from the upper part 112a. Therefore, even if the nucleic acid amplification reaction container 100 is switched to the third arrangement, the reaction liquid 140 stays in the portion where the size of the diameter is “a” in the second region 112 and is retained in the second region 112 without moving to the first region 111. The reaction liquid 140 is heated in the second region 112. When the arrangement is retained in the second arrangement without being switched to the third arrangement, in step S104, the high-temperature oil in the nucleic acid amplification reaction container 100 rises and the low-temperature oil falls. Therefore, fluctuation tends to occur in the temperatures of the oil at both the ends of the container. However, as in this embodiment, if, in step S104, the arrangement is switched to the third arrangement in which the first region 111 and the second region 112 are in the horizontal state or the first region 111 is below the second region 112 in the direction in which the gravity acts and, in step S105, the arrangement is retained in the third arrangement, the fluctuation in the temperatures of the oil at both the ends of the container is reduced. Therefore, it is possible to maintain the first region 111 and the second region 112 at the respective temperatures. If the nucleic acid amplification reaction apparatus 1 is used in this way, it is possible to apply a heat cycle of high temperature and low temperature suitable for a nucleic acid amplification reaction to the reaction liquid 140. It is possible to more stably amplify nucleic acid.
In step S106, it is determined whether the number of times of the heat cycle has reached a predetermined number of cycles. Specifically, it is determined whether the procedure of step S103 to step S105 has been completed a predetermined number of times. In this embodiment, the number of times step S103 to step S105 are completed is determined according to the number of times it is determined “YES” in step S103 and step S105. When step S103 to step S105 are performed once, the heat cycle is applied to the reaction liquid 140 by one cycle. Therefore, the number of times step S103 to step S105 are performed can be set as the number of cycles of the heat cycle. Therefore, according to step S106, it is possible to determine whether the heat cycle has been applied to the reaction liquid 140 the number of times necessary for the target reaction.
When it is determined in step S106 that the heat cycle has been performed the predetermined number of cycles (YES), the processing is completed (END). When it is determined in step S106 that the heat cycle has not been performed the predetermined number of cycles (NO), the processing shifts to step S107.
In step S107, the arrangement of the mounting section 11, the first heating section 12, and the second heating section is switched from the third arrangement to the first arrangement. By driving the main body 10 with the driving mechanism 20, it is possible to switch the arrangement of the mounting section 11, the first heating section 12, and the second heating section 13 to the first arrangement. When the arrangement of the mounting section 11, the first heating section 12, and the second heating section 13 reaches the first arrangement, step S103 is started.
When step S103 is performed following step S107, that is, when step S103 is performed for the second and subsequent times, it is determined whether time after the arrangement of the mounting section 11, the first heating section 12, and the second heating section 13 reaches the first arrangement has reached the first time.
A direction in which the mounting section 11, the first heating section 12, and the second heating section 13 are rotated by the driving mechanism 20 is preferably opposite directions in the rotation in step S104 and the rotation in step S107. Consequently, it is possible to eliminate a twist caused in wires such as the lead wires 15 by the rotation. Therefore, it is possible to suppress deterioration of the wires. The direction of the rotation is preferably reversed for each one operation by the driving mechanism 20. Consequently, it is possible to reduce a degree of the twist of the wires compared with when the rotation in the same direction is continuously performed a plurality of times.
Before the arrangement is switched from the second arrangement to the third arrangement in step S104, it may be determined whether the reaction liquid 140 is located in the second region 112. For example, after the arrangement is switched to the second arrangement, the arrangement is switched to the third embodiment when it is determined that the reaction liquid 140 is located in the second region 112, and the second arrangement is maintained when it is determined that the reaction liquid 140 is not located in the second region 112. The determination whether the reaction liquid 140 is located in the second region 112 of the nucleic acid amplification reaction container 100 can be performed by, for example, arranging a sensor (e.g., a fluorescence sensor), which senses reaction liquid, in the second region 112 of the nucleic acid amplification reaction container 100 and detecting the reaction liquid. In step S104, it is possible to surely heat the reaction liquid 140 at the second temperature by determining whether the reaction liquid 140 is located in the second region 112.
The nucleic acid amplification reaction apparatus 2 is the same as the nucleic acid amplification reaction apparatus 1 except that the nucleic acid amplification reaction container 200 shown in the sectional view of
Also in step S104 in this embodiment, after being switched from first arrangement to second arrangement, the arrangement of the mounting section 11, the first heating section 12, and the second heating section 13 is switched from the second arrangement to the third arrangement. The first arrangement to the third arrangement in step S104 in using the nucleic acid amplification reaction apparatus 2 are shown in
In step S107, when the nucleic acid amplification reaction apparatus 1 is used, the arrangement is switched from the third arrangement to the first arrangement. However, when the nucleic acid amplification reaction apparatus 2 is used, after being switched from the third arrangement (
In this embodiment, the step 212c having the surface perpendicular to the axis of the nucleic acid amplification reaction container 200 is provided. Therefore, it is possible to more surely keep the reaction liquid 240 in the second region than a form in which the slope 112c is provided as in the nucleic acid amplification reaction container 100.
As another form, the first arrangement may be arrangement in which the second region 212 is above the first region 211 in the direction in which the gravity acts and the side surface on which the step 212c is provided is above the other side surface in the direction in which the gravity acts. In that case, when the nucleic acid amplification reaction apparatus 2 is used as well, in step S107, it is possible to switch the arrangement to the first arrangement from the third arrangement (
Note that, in this specification, concerning two points, “above in the direction in which the gravity acts” and “below in the direction in which the gravity acts” only have to mean that there is a difference between the two points only about the direction in which the gravity acts. A straight line connecting the two points may be parallel to or may not be parallel to the direction in which the gravity acts.
The invention is not limited to the embodiment explained above and various modifications of the embodiment are possible. For example, the invention includes components substantially the same as the components explained in the embodiment (for example, components having functions, methods, and results same as the functions, the methods, and the results of the components explained in the embodiment or components having objects and effects same as the objects and the effects of the components explained in the embodiment). The invention includes components in which unessential portions of the components explained in the embodiment are replaced. The invention includes components that attain action and effects same as the action and effects of the components explained in the embodiment or components that can attain objects same as the objects of the components explained in the embodiment. The invention includes components obtained by adding publicly-known techniques to the components explained in the embodiment.
The entire disclosure of Japanese Patent Application No. 2014-109855, filed May 28, 2014 is expressly incorporated by reference herein.
Number | Date | Country | Kind |
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2014-109855 | May 2014 | JP | national |