Apparatus for high-speed nucleic acid amplification and method for temperature control of nucleic acid amplification reaction
11173491 · 2021-11-16
Assignee
Inventors
- Byoung Yeon WON (Seoul, KR)
- SangHyun PARK (Seoul, KR)
- Youn Tae Im (Chuncheon-si, KR)
- Jae Un AN (Incheon, KR)
- Bong Kyu Lee (Seoul, KR)
- Jae-ho Lee (Chuncheon-si, KR)
- Hanseung Jeong (Seoul, KR)
Cpc classification
B01L7/54
PERFORMING OPERATIONS; TRANSPORTING
B01L9/06
PERFORMING OPERATIONS; TRANSPORTING
B01L2200/147
PERFORMING OPERATIONS; TRANSPORTING
B01L7/52
PERFORMING OPERATIONS; TRANSPORTING
C12Q1/6848
CHEMISTRY; METALLURGY
B01L2300/1805
PERFORMING OPERATIONS; TRANSPORTING
B01L3/50855
PERFORMING OPERATIONS; TRANSPORTING
International classification
B01L7/00
PERFORMING OPERATIONS; TRANSPORTING
B01L9/06
PERFORMING OPERATIONS; TRANSPORTING
Abstract
The present invention relates to an apparatus for nucleic acid amplification and, more particularly, to an apparatus for nucleic acid amplification capable of rapid nucleic acid amplification by rapidly heating and cooling a reactant in a reaction vessel for a chemical/biochemical reaction requiring a temperature change, and a method for temperature control in nucleic acid amplification.
Claims
1. A high-speed nucleic acid amplification apparatus for use in a high-speed nucleic acid amplification reaction, the apparatus comprising: a holder configured to fix a position of a tube in which a reaction occurs; a heating module comprising a heater configured to generate heat so as to heat the tube and a heating block connected to the heater; a drive module configured to vertically move the heating module so as to vary a distance between the heating module and the holder; and a cooling module configured to cool the tube fixed to the holder, wherein: the cooling module comprises a blower fan configured to generate a cooling airflow and a blower nozzle configured to transfer the cooling airflow generated by the blower fan to the tube fixed to the holder, and the blower nozzle is closed when the heating module is disposed adjacent to the holder and is opened when the heating module is spaced apart from the holder.
2. The apparatus according to claim 1, wherein: the heating block is disposed below the holder and comprises at least one recess formed to allow at least a portion of the tube to be introduced thereinto; and the drive module moves the heating block to vary a distance between the recess and the tube.
3. The apparatus according to claim 2, wherein: the holder comprises at least one mounting hole vertically formed in the holder and having a predetermined inner diameter; the tube is mounted in the mounting hole so that a lower portion of the tube is exposed downward; and the lower portion of the tube is introduced into the recess when the heating block is raised, and the lower portion of the tube is spaced apart from the recess when the heating block is lowered.
4. The apparatus according to claim 1, wherein: the heating module further comprises a guide unit disposed on a side of the heater; and the guide unit comprises a guide pipe having a hole vertically formed therein, a guide beam inserted into the hole in the guide pipe to vertically extend, and an elastic spring located on the guide pipe so that the guide beam is inserted thereinto.
5. The apparatus according to claim 1, wherein: the heating block is disposed below the holder; the blower nozzle is disposed on one lateral side of the holder; the heating module comprises an opening and closing block; and the opening and closing block closes the blower nozzle when the heating block is raised, and is downwardly spaced apart from the blower nozzle to open the blower nozzle when the heating block is lowered.
6. The apparatus according to claim 3, wherein: the holder comprises a plurality of mounting holes arranged in parallel to form one or more alignment lines; the blower nozzle comprises an inlet adjacent to the blower fan and an outlet adjacent to the holder; the outlet has a wider horizontal width than a horizontal width of the inlet; and the outlet of the blower nozzle is horizontally disposed outside the holder, and the outlet has a width direction parallel to the alignment lines of the mounting holes.
7. The apparatus according to claim 1, further comprising: a sensing module configured to sense a reaction signal of a reactant in the tube; and a cover module disposed on the holder and configured to be opened or closed, wherein the cover module comprises a light source configured to provide light to the tube, and the sensing module comprises a sensor configured to sense the light generated from the reactant in the tube.
8. The apparatus according to claim 7, wherein the cover module further comprises an excitation filter disposed below the light source, and the sensing module further comprises an emission filter disposed between the tube and the sensor.
9. The apparatus according to claim 7, wherein the heating block comprises a light transmitting portion formed in at least one direction so that the light generated in the tube is transmitted in at least one lateral direction.
10. The apparatus according to claim 1, further comprising a control device configured to control operations of the heating module, the drive module, and the cooling module.
11. A method of controlling a temperature of a nucleic acid amplification reaction in which denaturation performed at a first temperature and an annealing and extension reaction performed at a second temperature are repeated multiple times, the method comprising: heating a reaction vessel, in which a reactant used for the nucleic acid amplification reaction is accommodated, to a first temperature by bringing the reaction vessel into contact with a heating block consistently maintained at the first temperature for a predetermined time; and cooling the vessel to a second temperature by separating the vessel from the heating block by a predetermined distance so that the separated vessel is exposed to an artificial airflow for a predetermined time, wherein the heating and the cooling are repeated multiple times with respect to the vessel cooled to the second temperature.
12. The method according to claim 11, wherein, in the cooling, the heating block is at a fixed position, and the vessel is moved upward of the heating block to a predetermined position so as to realize the predetermined distance.
13. The method according to claim 12, wherein the artificial airflow is continuously provided.
14. The method according to claim 11, wherein in the cooling, the vessel is at a fixed position, and the heating block is moved downward of the vessel to a predetermined position so as to realize the predetermined distance.
15. The method according to claim 14, wherein the artificial airflow is provided only when the heating block is spaced apart from the vessel by the predetermined distance.
16. The method according to claim 11, wherein the second temperature ranges from 55° C. to 70° C. to cause annealing and extension to occur at the same time.
17. The method according to claim 11, wherein the predetermined time in the cooling is determined as t=4+2×e.sup.−(v-7.4)/6.2, where t is the predetermined time and v is a velocity of the artificial airflow.
18. A method of controlling a temperature in a nucleic acid amplification reaction in which one cycle consisting of denaturation performed at a first temperature, annealing performed at a second-first temperature, and extension performed at a second-second temperature is repeated multiple times, the method comprising: heating a vessel used for the nucleic acid amplification reaction to the first temperature by bringing the vessel into contact with a heating block consistently maintained at the first temperature for a predetermined time; cooling the vessel to the second-first temperature by separating the vessel from the heating block by a predetermined distance so that the separated vessel is exposed to an artificial airflow for a predetermined time; and heating the vessel to the second-second temperature by bringing the vessel into contact with the heating block for a predetermined time, and then separating the vessel from the heating block by a predetermined distance to cause the separated vessel to be kept stationary in air for a predetermined time, wherein the heating, the cooling, and the keeping the vessel stationary are repeated multiple times.
19. The method according to claim 18, wherein, in the cooling or in the keeping the vessel stationary, when the vessel and the heating block are separated from each other by the predetermined distance, the heating block is at a fixed position, and the vessel is moved upward of the heating block to a predetermined position so as to realize the predetermined distance.
20. The method according to claim 19, wherein the artificial airflow is continuously provided.
21. The method according to claim 18, wherein, in the cooling or in the keeping the vessel stationary, when the vessel and the heating block are separated from each other by the predetermined distance, the vessel is at a fixed position, and the heating block is moved downward of the vessel to a predetermined position so as to realize the predetermined distance.
22. The method according to claim 21, wherein the artificial airflow is provided only when the heating block is spaced apart from the vessel by the predetermined distance.
23. The method according to claim 18, wherein the predetermined time in the cooling is determined as t=4+2×e.sup.−(v-7.4)/6.2, where t is the predetermined time and v is a velocity of the artificial airflow.
24. The method according to claim 11, wherein the predetermined distance ranges from 0.5 cm to 2 cm.
25. The method according to claim 19, wherein the predetermined time in the cooling is determined as t=4+2×e.sup.−(v-7.4)/6.2, where t is the predetermined time and v is a velocity of the artificial airflow.
26. The method according to claim 20, wherein the predetermined time in the cooling is determined as t=4+2×e.sup.−(v-7.4)/6.2, where t is the predetermined time and v is a velocity of the artificial airflow.
27. The method according to claim 21, wherein the predetermined time in the cooling is determined as t=4+2×e.sup.−(v-7.4)/6.2, where t is the predetermined time and v is a velocity of the artificial airflow.
28. The method according to claim 22, wherein the predetermined time in the cooling is determined as t=4+2×e.sup.−(v-7.4)/6.2, where t is the predetermined time and v is a velocity of the artificial airflow.
29. The method according to claim 18, wherein the predetermined distance ranges from 0.5 cm to 2 cm.
30. The method according to claim 12, wherein the predetermined time in the cooling is determined as t=4+2×e.sup.−(v-7.4)/6.2, where t is the predetermined time and v is a velocity of the artificial airflow.
31. The method according to claim 13, wherein the predetermined time in the cooling is determined as t=4+2×e.sup.−(v-7.4)/6.2, where t is the predetermined time and v is a velocity of the artificial airflow.
32. The method according to claim 14, wherein the predetermined time in the cooling is determined as t=4+2×e.sup.−(v-7.4)/6.2, where t is the predetermined time and v is a velocity of the artificial airflow.
33. The method according to claim 15, wherein the predetermined time in the cooling is determined as t=4+2×e.sup.−(v-7.4)/6.2, where t is the predetermined time and v is a velocity of the artificial airflow.
34. The method according to claim 16, wherein the predetermined time in the cooling is determined as t=4+2×e.sup.−(v-7.4)/6.2, where t is the predetermined time and v is a velocity of the artificial airflow.
Description
DESCRIPTION OF DRAWINGS
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MODE FOR INVENTION
(29) Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments are illustrative and are not intended to limit the present invention in any way.
(30)
(31) The nucleic acid amplification apparatus according to the present invention is a nucleic acid amplification apparatus that controls the temperature of a reactant accommodated in a tube T, and includes the casing 100 defining the external appearance of the apparatus, the tube T being at a fixed position on at least a portion of the casing, a heating module 200 located below the tube T and configured to generate heat so as to heat the tube T, a sensing module 300 configured to sense light generated in the tube heated by the heating module 200, a drive module 400 configured to vertically move the heating module 200 so as to vary a distance between the tube T and the heating module 200, a cooling module 500 configured to cool the reactant accommodated in the tube T, the cover module 600 disposed on the casing 100 and capable of providing light to the tube T, and a control device 700 configured to control the operation of the entire apparatus.
(32) The casing 100 may have a hexahedral shape, and may include a lower plate 110 forming a bottom surface, an upper plate 120 forming an upper surface, and a side plate 130 forming a side surface. A holder 150, the heating module 200, the sensing module 300, the drive module 400, the cooling module 500, and the control device 700, which will be described later, may be mounted inside the casing 100.
(33) The upper plate 120 may have an introduction opening 122 formed in the vertical direction so that the holder 150 is exposed upward. The tube T may be mounted at a fixed position in the holder 150 exposed through the introduction opening 122. In addition, the cover module 600 may be pivotably connected to the upper plate 120 to open or close a mounting hole 154. The specific configuration of the cover module 600 will be described later.
(34) The upper plate 120 and the cover module 600 may be connected to each other by a hinge 160. In addition, the upper plate 120 may be provided with a fastener 124, which fastens the cover module 600 to the upper plate 120, and may also be provided with a display device 140, which displays the operational state of the apparatus.
(35) The holder 150 may be disposed inside the casing 100, and may be exposed upward through the introduction opening 122 formed in the casing 100.
(36) The holder 150 includes a holding body 152 in the form of a block. The holding body 152 may be fixed at a position on at least a portion of the casing 100. In addition, the holding body 152 may be provided with the mounting hole 154 in the upper surface thereof. The mounting hole 154 may be vertically formed, or may be recessed downward. Thus, the tube T in which a sample is accommodated may be mounted at a fixed position in the mounting hole 154. A plurality of mounting holes 154 may be provided and may be arranged to form a line. For example, as illustrated in the drawings, eight mounting holes 154 may be arranged in a line.
(37) When the mounting hole 154 is vertically formed and the tube T is mounted in the mounting hole 154, a lower portion of the tube T may protrude downward from the holder 150 to thereby be exposed. In addition, the plurality of mounting holes 154 may be arranged to form a predetermined number of lines in parallel.
(38) In addition, a fixing jig 156 may be provided to fix the holding body 152 to the lower surface of the upper plate 120 of the casing 100.
(39) In addition, the casing 100 may be provided with a signal input/output device 170, which is capable of receiving and transmitting an electric signal, and a power supply device 180, which is capable of supplying power.
(40) The heating module 200 may be located below the holder 150 and is capable of heating the reactant accommodated in the tube T mounted in the holder 150.
(41) The heating module 200 is a three-dimensional structure, which may be shifted by the drive module 400, which will be described later. The heating module 200 may include a heater 210, a heating block 220 disposed above the heater 210, a guide unit 230 disposed on a side of the heater 210, and an opening and closing block 240 disposed above the heater 210.
(42) The heater 210 serves to generate heat to heat the reactant accommodated in the tube T. For example, the heater may be operated in response to an electric signal generated in the control device 700. The heater 210 may be controlled to generate heat at a correct temperature as desired by the user. The heater 210 may be configured to have, for example, a Peltier element, without limitation thereto.
(43)
(44) The recesses 222 are formed in the top of the heating block 220. The recesses 222 are formed at positions corresponding to the positions of the mounting holes 154 formed in the holder 150. The multiple recesses 222 may be formed to form a predetermined number of lines in parallel. For example, as described above, when eight mounting holes 154 are formed and arranged in a line, eight recesses 222 may also be formed and arranged in a line. In addition, each recess 222 may have a shape corresponding to the lower portion of the tube T so that the lower portion of the tube T may be introduced into and come into close contact with the recess 222.
(45) The light transmitting portions 224 are formed in at least one side of the respective recesses 222 and take the form of passages which penetrate the recesses in the lateral direction. For example, the light transmitting portions 224 may be formed at the rear of the recesses 222, and may be passages which penetrate a rear portion of the heating block 220 in the front-and-rear direction.
(46) The guide unit 230 may be connected to the lateral side of the heater 210. The guide unit 230 may include a guide pipe 232, a guide beam 234, and an elastic spring 236.
(47) The guide pipe 232 included in the heating module 200 has a guide hole vertically formed therein and is fixed to the lateral side of the heater 210.
(48) The guide beam 234 of the heating module 200 vertically extends through the guide hole. For example, the guide beam 234 may have a lower end fixed to the lower plate 110 and an upper end fixed to the upper plate 120 or the fixing jig 156.
(49) The elastic spring 236 is disposed between the guide pipe 232 and the upper plate 120 so that the guide beam 234 passes through the elastic spring 236. Thus, when the elastic spring 236 is compressed, the elastic spring 236 applies an elastic force downward to the guide pipe 232. In other words, the elastic spring 236 may apply an elastic force to maintain the guide pipe 232 at the lowered position thereof. In addition, the elastic spring 236 prevents strong collision between the heating block 220 and the tube T when the heater 210 and the heating block 220 move upward, and may bring the heating block 220 and the tube T into close contact with each other.
(50) The opening and closing block 240 includes an upright shield having a predetermined height and a predetermined thickness. The opening and closing block 240 is disposed above the heater 210 at the lateral side of the heating block 220. The opening and closing block 240 may be vertically erected to have a predetermined height and may be located between a blower nozzle 520 and the heating block 220.
(51) The sensing module 300 may include a module housing 310, a light capturing unit 320, and an emission filter 330. The sensing module 300 may be disposed on the heater 210 of the heating module 200 and may be shifted along with the heating module 200.
(52) The module housing 310 may include a module cover 312 and a module base 314. The module housing 310 may be configured to accommodate the light capturing unit 320 and the emission filter 330 therein.
(53) The heating block 220 may also be mounted inside the module housing 310, and the module cover 312 may have an upwardly open space so as to upwardly expose the recesses 222 in the heating block 220. In addition, the module base 314 includes a mounting wall 316 to which the heating block 220 is coupled, and the light capturing unit 320 and the emission filter 330 are also mounted to the mounting wall 316. A through-hole 318 may be formed in the mounting wall 316 at a position corresponding to the position of each light transmitting portion 224 in the heating block 220 so as to communicate with the light transmitting portion 224.
(54) The light capturing unit 320 may be configured in such a manner that sensors 324 are mounted on a printed circuit board (PCB) 322. The sensors 324 may be, for example, photodiodes and the number and arrangement of sensors 324 may correspond to the number and arrangement of light transmitting portions 224. That is, eight light transmitting portions 224 may be formed to correspond to the number of recesses 222 in the heating block 220, and eight sensors 324 may be provided to correspond to the respective light transmitting portions 224. For example, as illustrated in
(55) The emission filter 330 may be disposed between the light capturing unit 320 and the heating block 220. The emission filter 330 is a band-pass filter that passes only the light of the wavelength generated by a fluorescent material of the tube due to incident light. Thus, the light generated in the tube may pass through the light transmitting portion 224 and the emission filter 330 behind the heating block 220 to thereby be introduced into the sensor 324 of the light capturing unit 320.
(56) The drive module 400 serves to shift the heating module 200 and the sensing module 300.
(57) The drive module 400 is located below the heating module 200. The drive module 400 may include a motor 410 and a motor shaft 420, for example. The motor shaft 420 is connected to a lower portion of the heating module 200. When the motor 410 is operated, the motor shaft 420 may be moved upward to shift the heating module 200 upward. Needless to say, the present invention is not limited thereto, and the drive module 400 may have any other configuration as long as it may shift the heating module 200 and the sensing module 300.
(58) With the operation of the drive module 400, the heating module 200 and the sensing module 300 may reciprocate between the raised position and the lowered position thereof. For example, when the drive module 400 moves upward, the heating module 200 and the sensing module 300 may be moved to the raised position. When the drive module 400 moves downward, the heating module 200 and the sensing module 300 may be moved to the lowered position.
(59) The cooling module 500 includes a blower fan 510 and the blower nozzle 520.
(60) The blower fan 510 serves to generate an airflow to cool the tube T. The blower fan 510 may include a propeller and the motor 410, although not illustrated.
(61) The blower nozzle 520 serves to transmit the airflow generated by the blower fan 510 to the tube T mounted in the holder 150. The blower nozzle 520 is configured to have a predetermined inner space penetrating in opposite directions. One side of the space functions as an inlet 522 and is disposed adjacent to the blower fan 510, and the other side of the space functions as an outlet 524 and is disposed adjacent to the holder 150.
(62) As illustrated in
(63) The outlet 524 of the blower nozzle 520 may be located parallel to the arrangement of a plurality of tubes T mounted in the holder 150 and may be configured to uniformly provide cooling air to the plurality of tubes T mounted in the holder 150.
(64) That is, referring to
(65) The cover module 600 is a cover that is pivotably connected to the upper plate 120 of the casing 100 via the hinge 160, as described above. Hereinafter, the cover module 600 will be described with reference to
(66) The entire cover housing 610 may have a rectangular parallelepiped shape, and may include a housing portion 612 having a predetermined space therein and an opening and closing cover 614 connected to the housing portion 612 so as to be opened and closed.
(67) The cover base 620 is mounted inside the cover housing 610. When the opening and closing cover 614 is opened, at least a portion of the cover base 620 is exposed. The cover base 620 has a filter insertion slot 622 and light passages 624. The filter insertion slot 622 is formed in the front surface of the cover base 620, and has a predetermined depth in the rearward direction and a predetermined width in the lateral direction. The light passages 624 are formed so as to extend vertically through the filter insertion slot 622.
(68) The light emitting unit 630 includes a PCB 632 and a plurality of light sources 634 mounted on the lower surface of the PCB 632. The PCB 632 is mounted on the upper surface of the cover base 620 as illustrated by the arrow B in
(69) The arrangement of the light passages 624 and the light sources 634 may be the same as the arrangement of the recesses 222 in the heating block 220. That is, eight light sources 634 and eight light passages 624 may be arranged in a line above the recesses 222 to correspond to the arrangement in which eight recesses 222 are arranged in a line.
(70) The excitation filter 650 is an optical band-pass filter having a predetermined thickness and a predetermined area. The excitation filter 650 passes only light of a specific wavelength, suitable for a fluorescent material used for a reaction occurring in the apparatus, of broadband light emitted from the light sources 634 of the light emitting unit 630 and causes the light to be introduced into the reactant in the tube. The filter may be inserted into the filter insertion slot 622 formed in the cover base 620 as illustrated by the arrow A in
(71) The tube cap heating element 640 is mounted on the lower surface of the cover base 620 as illustrated by the arrow C in
(72) The control device 700 may be a CPU capable of controlling the operation of the heating module 200, the sensing module 300, the drive module 400, and the cooling module 500. The control device 700 may control the operation of the heating module 200, the sensing module 300, the drive module 400, and the cooling module 500 upon receiving an external signal, and may output the operational state.
(73) Hereinafter, the operation of the nucleic acid amplification apparatus according to the present invention will be described.
(74) First, the tube T in which a reactant is accommodated is mounted in the holder 150. At this time, the tube T may be mounted by opening the cover module 600 on the casing 100, introducing the tube T into the mounting hole 154 in the holder 150 to mount the tube T, and thereafter, closing the cover module 600.
(75) At this time, as illustrated in
(76) The heating module 200, the sensing module 300, the drive module 400, the cooling module 500, and the cover module 600 may be operated when an operation signal is generated by the control device 700. Alternatively, respective operations may be performed at the same time or may be performed with a time difference, and the implementation manner thereof is not limited.
(77) When the operation signal is transmitted to the heating module 200, the heater 210 may be operated to generate heat. In addition, when an operation signal is transmitted to the drive module 400, the motor 410 is operated to raise the heating module 200. Thereby, the heating module 200 is moved to the raised position thereof as illustrated in
(78) When the heating module 200 is raised by the drive module 400 and the heating block 220 of the heating module 200 approaches the holder 150, the reactant in the tube T mounted in the holder 150 is heated. At this time, the surface of the recess 222 formed in the heating block 220 and the lower surface of the tube T may be in contact with each other to enable rapid heat transfer.
(79) At this time, since it is not necessary to cool the tube T when the heating module 200 is raised, the blower fan 510 of the cooling module 500 may be stopped.
(80) Alternatively, according to one example, when the heating module 200 is raised, the opening and closing block 240 of the heating module 200 is raised. The raised opening and closing block 240 may close the outlet 524 in the blower nozzle 520 of the cooling module 500 so as to prevent cooling air generated by the cooling module 500 from being transmitted to the tube T.
(81) At this time, as illustrated in
(82) When the heating module 200 is maintained at the raised position for a predetermined time and a designated heating time elapses, the control device 700 may generate a signal to reversely operate the motor 410 of the drive module 400.
(83) When the motor 410 of the drive module 400 is reversely operated, the heating module 200 is lowered. As the heating module 200 is lowered, the tube T and the heating block 220 are spaced apart from each other and the heating of the tube T by the heating block 220 is stopped. Here, the term “stop” is not limited to the meaning that heat transfer is completely excluded.
(84) When the heating module 200 is lowered, the blower fan 510 is operated to cool the tube T. Alternatively, according to one example, when the opening and closing block 240 provided in the heating module 200 is lowered, the outlet 524 in the blower nozzle 520 is opened so that the tube T mounted in the holder 150 may be cooled by the cooling airflow generated by the blower fan 510.
(85) When the heating module 200 is maintained at the lowered position for a predetermined time and a designated cooling time elapses, the control device 700 generates a signal to operate the drive module 400 again so that the heating block 220 is raised to heat the reactant in the tube T mounted in the holder 150. Then, when a heating time elapses, the heating block 220 is lowered as described above and the tube is exposed to the air so as to be cooled. This process is repeated a predetermined number of times.
(86) According to the present invention, the temperature of the reactant may be rapidly controlled. That is, the tube T in which the reactant is accommodated may be brought into contact with the heating block 220 of the heating module 200 so as to be rapidly heated. When the heating is sufficiently performed, the heating module 200 or the holder is moved to open the blower nozzle 520 so that the reactant may be rapidly cooled by the cooling air generated in the blower fan 510.
(87) In addition, when the operation of the heating module 200 or the holder 150 is set according to user intention, the heating time and the cooling time of the reactant may be controlled so that the reactant reaches any of various target temperatures and a target temperature range may be maintained. For example, when the operation cycle of the heating module 200 is changed or when the time during which the heating module 200 is maintained at the raised position thereof or the time during which the heating module 200 is maintained at the lowered position are set differently, the heating time and cooling time of the reactant may be set differently so that the temperature of the reactant may be easily controlled and selected as desired by the user.
(88) In addition, the heating and cooling of the reactant may be achieved with a very simple operation. That is, when the heating block 220 and the opening and closing block 240 provided in the heating module 200 are raised and lowered together at the time of heating, the heating block 220 may approach the tube T to perform rapid heating and the opening and closing block 240 may close the blower nozzle 520 to prevent cooling by the cooling airflow. In addition, at the time of cooling, the heating block 220 is spaced apart from the tube T to stop the heating, and the opening and closing block 240 is spaced apart from the blower nozzle 520 to open the blower nozzle 520 so that rapid cooling by the cooling airflow is achieved. In this way, the heating and cooling of the reactant may be appropriately performed simply by an operation signal for the drive module 400 which moves the heating module 200 without requiring the input of a separate cooling operation signal.
(89) In addition, in the heating process, the light generated in the light source 634 of the cover module 600 is incident on the reactant in the tube T and the light generated in the reactant is transmitted to and sensed by the sensor 324, whereby the reaction result of the reactant may be detected in real time.
(90) Accordingly, a polymerase chain reaction (PCR), which is a typical chemical and biochemical reaction requiring temperature control may be performed rapidly and accurately.
(91) In another aspect, the present invention also relates to a method of controlling the temperature of a reaction solution in a nucleic acid amplification reaction.
(92) The method according to the present invention may be performed using the apparatus as described above or an apparatus exemplified in
(93) In the method according to the present invention, heating and cooling are performed using separate devices in such a manner that a reaction vessel in which a reaction solution is accommodated is moved between a heating block maintained at a high temperature and an airflow generated by a blower fan so as to be repeatedly exposed to the heating block and the airflow, which results in temperature control.
(94) The method according to the present invention may be used for temperature control in a technology of amplifying a target specific nucleic acid using a periodic temperature change, for example, a polymerase chain reaction (PCR). In such a PCR, generally, three reaction steps constitute one cycle, and the cycle is repeated at least 2 times, at least 2 to 50 times, at least 2 to 40 times, or at least 2 to 30 times, without limitation thereto. The PCR is a process of amplifying a small amount of target to enable detection thereof, and may be performed in various ways according to the amount of a target present in a sample, the degree of impurities contained in the sample, the type of a detection method, the purpose of detection, the type of enzymes, and PCR conditions, and those skilled in the art will be able to determine the number of cycles suitable for such conditions.
(95) To explain, in a first denaturation step, a double-stranded nucleic acid is divided into single strands at a temperature of 90° C. or higher. A second annealing step usually takes place at 55° C. to 60° C., in which two types of primers are bound to complementary portions of the respective nucleic acid strands which have been separated into single strands in the denaturation step. In a third extension step, extension in which a DNA polymerase synthesizes a DNA using a single strand as a template and using base monomers (dNTPs) from a primer. At this time, the temperature usually ranges from 65° C. to 75° C. That is, the PCR usually proceeds within a temperature range of 55° C. to 95° C. while repeating a temperature change for heating and cooling, and the target nucleic acid is amplified by repeating this heating and cooling process 25 to 40 times. In the PCR, the annealing and extension steps may be performed in one step according to a specific temperature, in which case one cycle consists of two steps including a denaturation step and an annealing and extension step. The present invention may be applied to both the methods described above.
(96) The PCR method as described above may be divided into two manners as described in
(97) The method according to the present invention is particularly optimized for the PCR in the latter manner. Such a method may exhibit somewhat low sensitivity or specificity as compared to conventional methods, but may be very conveniently used for applications in which large quantities of samples need to be screened quickly.
(98) Accordingly, in one aspect, the present invention relates to a method of controlling the temperature of a nucleic acid amplification reaction including a denaturation step performed at a first temperature and an annealing and extension reaction step performed at a second temperature, these steps being repeated multiple times.
(99) In one embodiment, the method includes a first step of heating a vessel used for a nucleic acid amplification reaction to a first temperature by bringing the vessel into contact with a heating block consistently maintained at the first temperature for a predetermined time, and a second step of cooling the vessel to a second temperature by separating the heating block from the vessel by a predetermined distance so that the separated vessel is exposed to an artificial airflow for a predetermined time, and the first and second steps are repeated multiple times with respect to the vessel cooled to the second temperature.
(100) Alternatively, in another aspect, the present invention relates to a method of controlling the temperature of a PCR in three steps, i.e., a denaturation step performed at a first temperature, an annealing step performed at a second-first temperature, and an extension step performed at a second-second temperature, which constitute one cycle.
(101) In one embodiment, the method includes a first step of heating a vessel used for a nucleic acid amplification reaction to a first temperature by bringing the vessel into contact with a heating block consistently maintained at the first temperature for a predetermined time, a second step of cooling the vessel to a second-first temperature by separating the vessel from the heating block by a predetermined distance so that the separated vessel is exposed to an airflow for a predetermined time, and a third step of cooling the exposed vessel to a third temperature by exposing the vessel to an airflow for a predetermined time.
(102) Recently, large quantities of samples are used for the purpose of screening, and a rapid reaction is essential for this. In the PCR, however, temperature control during the heating and cooling process is a key factor in achieving a rapid reaction.
(103) In the method according to the present invention, in a first step, a reaction vessel in which a reaction solution is accommodated comes into contact with a heating block, maintained at a specific temperature for a predetermined time, so as to be heated for a predetermined time until the reaction solution reaches a target denaturation temperature. Subsequently, in a second step, the vessel is separated from the heating block and is moved in a predetermined direction so as to be exposed to an artificial airflow generated by a blower fan for a predetermined time until the reaction solution is cooled to reach a target cooling temperature. At this time, the temperature of the reaction solution may be controlled to reach various target temperatures by controlling the contact time with the heating block or the contact time with the airflow generated by the blower fan. By repeating this process, the temperature of the reaction solution may be controlled so as to repeatedly reach specific temperature ranges.
(104) In one embodiment, the artificial airflow generated by the blower fan, i.e., the wind, is at room temperature. The room temperature may vary somewhat for each environment, but the velocity of the airflow may be controlled via the RPM of the fan that generates the airflow using an outside temperature measurement thermometer attached to the apparatus. In addition, when used in a room, considering the temperature condition of the PCR, there is substantially no difference in cooling time when the temperature of the airflow is 20° C., 30° C., or 35° C. within the PCR temperature range of 55° C. to 65° C. On the other hand, the velocity of the airflow may affect the cooling time.
(105) The time required to cool the reaction solution, heated to 98° C. for nucleic acid denaturation, to a general annealing or extension temperature of 65° C., i.e., a predetermined time for the exposure of the reaction solution to the artificial airflow, is related to the velocity of the airflow blown toward the reaction vessel. In one embodiment, the cooling time may be determined by the following equation: t=4+2×e.sup.−(v-7.4)/6.2.
(106) For example, when a standard PCR tube for a general PCR is used as a reaction vessel and a reaction solution of 20 μl is used, the time t required for cooling the reaction solution from 98° C. to 65° C. as illustrated in
(107) In the present invention, the temperature is based on the reaction solution or a reactant accommodated in the reaction vessel. However, due to the characteristics of the PCR by the method according to the present invention, it can be said that there is no difference in the temperature between the vessel and the solution in consideration of the material of a general PCR tube which shows excellent heat transfer and has a very small volume of about 1 μl to 50 μl. Thus, unless otherwise specified herein, the temperature of the reaction vessel refers to the temperature of the reactant or the reaction solution.
(108) In one embodiment, the method according to the present invention may be performed using the apparatus described above as illustrated in
(109) A first step of the method according to the present invention includes heating the reactant in the reaction vessel to a first temperature.
(110) In the method according to the present invention, the reactant is accommodated in the reaction vessel, and the reaction vessel may differ according to the specific configuration of the apparatus which implements the method according to the present invention, but may use, for example, a tube having a capacity of 100 μl or 200 μl, a capillary tube, a microfluidic channel, or a thin film chamber, which is generally used in a PCR, without limitation thereto.
(111) The first temperature in the first step of the method according to the present invention means a temperature sufficient to separate a double-stranded DNA into single strands in a nucleic acid amplification reaction. The first temperature may be determined by various factors such as the composition of a base constituting a DNA, e.g., a G/C composition ratio, the total length, or the concentration of salt contained in a buffer, and those skilled in the art will be able to select an appropriate temperature in consideration of reaction conditions, for example. For example, the first temperature may be not lower than 90° C. or may be about 95° C., without limitation thereto.
(112) The heating of the reactant in the first step of the process according to the present invention may be performed using the heating block. In particular, the heating block is fixed at the first temperature and does not require a temperature change, thus allowing a rapid reaction. The heating block is formed, for example, to have a structure as illustrated in
(113) In the method according to the present invention, the reaction solution is the subject of temperature change. The PCR by the method according to the present invention may be rapidly performed compared to a conventional PCR on the basis of a general PCR execution volume of 20 μl under the assumption that a generally used polypropylene reaction vessel is used and currently used general conditions (tube and volume) are equally applied. In addition, the method of the present invention may also be applied when a reaction vessel, which is formed of any another material or any another shape (such as a microfluidic device) is used or when a reaction solution having a volume other than 20 μl is applied. In this case, the method may proceed quickly compared to a Peltier-based temperature control method using a single heating or cooling source.
(114) When a different vessel or a different volume is applied, the ramping rate (the degree of temperature change per second) may vary due to the characteristics of the method of the present invention. The heating or cooling time may be experimentally determined by acquiring the ramping rate depending on a volume change or material characteristics.
(115) In a first step of the method according to the present invention, a reaction vessel is brought into contact with a heating block, which is maintained at a temperature of about 100° C., for example, 95° C. required for denaturation of a nucleic acid, for a predetermined time. The term “predetermined time” as used herein means the time taken until the temperature of a reactant accommodated in a PCR tube widely used in a general PCR, for example, a thin-wall tube formed of polypropylene (e.g., MicroAmp® PCR tube of Thermo Fisher) reaches a temperature sufficient for the denaturation of a double-stranded DNA in a reaction solution via contact with the heating block, and may be determined in consideration of the volume of the reaction solution, and those skilled in the art will be able to select an appropriate time in consideration of specific reaction conditions. In one embodiment using the reaction solution having a volume of 20 μl, the contact time may range from 1 second to 15 seconds.
(116) In the method according to the present invention, after the first step, the reaction vessel and the heating block are separated from each other by a predetermined distance. In this process, the heating block and/or the reaction vessel may be moved. As illustrated in
(117) The distance is not particularly limited as long as the effect of the movement time on the total reaction time is minimized, and is determined so as to be suitable for exposure according to the position of a blower. Specifically, the distance is determined to prevent the temperature of the heating block from affecting the reaction vessel, for example, to allow the reaction vessel to be sufficiently spaced apart from the air around the heating block which is heated by the heating block and prevent a blown cooling airflow from reaching or coming into contact with the heating block and thus from having a negative effect on the maintenance of the temperature of the heating block. In one embodiment, the distance may range from 0.5 cm to 2 cm.
(118) After the heating block and the reaction vessel are separated from each other, the reaction vessel may be exposed to an artificial airflow for a predetermined time for cooling in a second step. Alternatively, the reaction vessel may remain stationary in the air for a predetermined time. The former is used in a two-step reaction in which annealing and extension are performed in one step, and the latter is used in a three-step reaction in which annealing and extension are separately performed.
(119) In one embodiment according to the present invention, annealing and extension are performed in one step, and the reaction vessel separated from the heating block is exposed to the artificial airflow for a predetermined time. The artificial airflow may be at room temperature, and may be provided by a fan-type device having a motor, for example, a general cooling fan, a blower fan, a cross fan, or an air compressor, without limitation thereto.
(120) In the second step of the method in which annealing and extension are performed in one step according to the present invention, a predetermined contact time is determined according to a second target temperature, for example, 55° C. to 70° C. Herein, the predetermined time in the second step refers to the time during which the reactant comes into contact with the airflow to reach an annealing or extension reaction temperature and may be determined in consideration of the volume of the reaction solution, and those skilled in the art will be able to select an appropriate time in consideration of specific reaction conditions. In one embodiment using the reaction solution having a volume of 20 μl, the contact time may range from 1 second to 15 seconds.
(121) Alternatively, in another embodiment according to the present invention, denaturation, annealing, and extension are performed, respectively. In this case, after a denaturation step performed at a first temperature, the heating block and the reaction vessel are separated from each other, and the reaction vessel is cooled to a second-first annealing temperature and then is heated again to a second-second elongation temperature. Thereafter, a third step of causing the reaction vessel to remain stationary at room temperature may be performed for a predetermined time.
(122) In this case, the method according to the present invention is a temperature control method in a nucleic acid amplification reaction in which one cycle consisting of a denaturation step performed at a first temperature, an annealing step performed at a second-first temperature, and an extension step performed at a second-second temperature is repeated multiple times. The method includes a first step of heating a vessel used for a nucleic acid amplification reaction to a first temperature by bringing the vessel into contact with a heating block consistently maintained at the first temperature for a predetermined time, a second step of cooling the vessel to a second-first temperature by separating the vessel from the heating block by a predetermined distance so that the separated vessel is exposed to an artificial airflow for a predetermined time, and a third step of heating the vessel to a second-second temperature via contact between the vessel and the heating block for a predetermined time and thereafter, separating the heating block from the vessel by a predetermined distance to cause the separated vessel to remain stationary in the air for a predetermined time.
(123) In the third step, the temperature of the reaction vessel is raised to an extension temperature, for example, 72° C. by the heating block, and thereafter, the reaction vessel is separated from the heating block and remains stationary in the air. The reaction vessel is brought into contact with the heating block twice, unlike the case in which annealing and extension are performed in one step, and the temperature of the reaction vessel may be adjusted by changing the contact time. For example, based on the volume of 20 μl, the heating block may come into contact with the reaction vessel for about 10 seconds to realize the denaturation temperature, for example, 91° C. in the first step, and may come into contact with the reaction vessel for about 3 seconds to realize the extension temperature, for example, 72° C. in the third step.
(124) In the step of separating the heating block and the reaction vessel from each other, the heating block or the reaction vessel may be moved so that the reaction vessel is exposed, as described above. For a description of this step, refer to the above description.
(125) While the exemplary embodiments of the present invention have been described in detail, it is to be understood that the scope of the present invention is not limited thereto and various modifications and improvements made by those skilled in the art using the basic concept of the present invention as defined in the following claims are also within the scope of the present invention.
Example 1: Temperature Control of Reaction Solution Based on Control of Contact Time of Heating Block and Reaction Vessel
(126) A high-speed temperature control method according to the present invention controls the temperature of a reaction vessel in which a reaction solution is accommodated by controlling the time of contact between a reaction vessel and a heating block or an airflow generated from a blower fan. With this method, the temperature of the reaction solution may be controlled to rapidly reach a target temperature.
(127) In this example, a temperature measuring device was attached to the reaction vessel in which the reaction solution is accommodated, and the reaction vessel was repeatedly moved to the heating block or to the front of the blower fan so as to come into contact with the heating block or an airflow from the blower fan for a predetermined time. A change in the temperature of the reaction solution for each contact time was measured. The composition of the reaction solution, the reaction vessel, and the heating block were as follows:
(128) Temperature measuring device: Pico technology (UK) TC-08 thermocouple data logger+thermocouple (K type); Reaction solution: 20 μl PCR buffer (10 mM Tris-HCl, pH 8.3+50 mM KCl+2 mM MgCl2); Reaction vessel: Bio-Rad 0.2 Ml tube strip (low profile); heating block: Bio-Rad c1000 thermal cycler (98° C. incubation setting); and blower fan: 3D-Manufactured 12 V, 0.15 A, and 1.8 W blower fan.
(129) As a result, by controlling the contact time between the heating block and the cooling medium as illustrated in
(130) In addition, repetitive temperature control is possible as illustrated in
(131) In the method according to the present invention, since the reaction vessel is quickly moved between the heating medium and the cooling medium, a relatively long time required for the temperature change of the heating medium or the cooling medium is not necessary, which allows the temperature change of a sample in the reaction vessel to be induced quickly, thus enabling a rapid reaction.
(132) In addition, temperature change may be realized in three steps when a stationary step of separating a tube in which a reaction solution is accommodated from a heating block but preventing the tube from coming into contact with an airflow is provided during contact with the heating block and the airflow.
Example 2. Detection of Target Nucleic Acid by High-Speed PCR Using Method According to Present Invention
(133) 2-1 Mycoplasma Pneumonia Detection
(134) A PCR mixture of 20 μl for the amplification of a Mycoplasma pneumonia sequence was added to a reaction vessel, and a process of bringing the reaction vessel into contact with a heating block for 8 seconds and with an airflow from a blower fan for 7 seconds was repeated 30 times. The reaction apparatus, the reaction conditions, and the composition of the reactant were as follows:
(135) Reaction Vessel: Bio-Rad 0.2 Ml tube strip (low profile)
(136) Heating Block: Bio-Rad c1000 thermal cycler (98° C. incubation setting)
(137) Blower fan: 3D-Manufactured 12 V, 0.15 A, and 1.8 W blower fan
(138) PCR Mixture Composition: forward and reverse primers, dNTP, PCR buffer (iNtRon), Taq polymerase (iNtRon), target DNA (Mycoplasma pneumonia cloned vector), enhancer, and evaGreen dye (Jena Bioscience)
(139) TABLE-US-00001 Primer Sequence: (forward) 5′-CAACCTCCATGTAGCTGATAG or (reverse) 5′-GGTGATATCGCCAGGTAAA
(140) High-Speed PCR Conditions: predenaturation 1 minute (98° C.), contact with the heating block (98° C.) for 8 seconds+contact with the airflow for 7 seconds, repetition of 30 times
(141) 10.sup.5˜10.sup.1 copies of a mycoplasma pneumonia target DNA were added respectively to reaction tubes, and negative control (NC) without a target DNA was also tested. After the high-speed PCR, amplification products were confirmed by melting curve analysis and electrophoresis, and the results are illustrated in
(142)
(143) The time taken to repeat temperature change 30 times for a PCR in this example was 7 minutes and 30 seconds, and the time required for the entire PCR, including a predenaturation time of 1 minute before the PCR, was 8 minutes and 30 seconds. This is a very short time compared to a PCR method using a conventional PCR apparatus which requires 30 minutes or more.
(144) 2-2 HBV Detection
(145) After preparing various concentrations of HBV sera by diluting an actual serum from an HBV patient, viral DNA was extracted from each serum and was mixed with a PCR solution. After the PCR solution of 20 μl to which each of viral DNAs of different concentrations had been added was added to a reaction tube strip to which PCR tubes were connected and tube caps were closed, a predenaturation step was performed for 1 minute using a heating block heated to 98° C. Next, a high-speed PCR was performed for HBV diagnosis by repeating the process of bringing the tubes into contact with the heating block for 8 seconds and bringing the tubes into contact with an airflow from a blower fan for 7 seconds 35 times. The reaction apparatus, the reaction conditions, and the composition of the reactant were as follows:
(146) HBV gDNA extraction: Gene All Exgene viral DNA/RNA mini kit (128-150);
(147) Reaction tubes: Bio-Rad 0.2 Ml tube strip (low profile);
(148) Heating block: Bio-Rad c1000 thermal cycler (98° C. incubation setting);
(149) Blower fan: four 3D-Manufactured blower fan of 12 V, 0.15 A, and 1.8 W+blower nozzle; PCR mixture composition: forward and reverse primers, dNTP, PCR buffer (iNtRon), Taq polymerase (iNtRon), target DNA (extracted Mycoplasma pneumonia gDNA), enhancer, and evaGreen dye (Jena Bioscience);
(150) Primer sequence: 5′-GATGT′K′TCTGCGGCGTTTTATC (forward, ‘K’=G or T) and 5′-CA′M′ACGGGCAACATACCTTG (reverse, ‘M’=A or C); and
(151) High-speed PCR: predenaturation 1 minute (98° C.), contact with the heating block (98° C.) for 8 seconds+contact with the airflow for 7 seconds, repetition of 35 times.
(152) After the high-speed PCR, the amplification products were confirmed by melting curve analysis and electrophoresis, and the results are illustrated in
(153)
(154) The time required for a high-speed PCR for the diagnosis of HBV infection in this example was 8 minutes and 45 seconds, and the time required for the entire PCR including one minute of predenaturation before a PCR was 9 minutes and 45 seconds. This is a very short time compared to a general PCR-based method proposed by an HBV detection kit (Abbott Realtime HBV amplification reagent) using a conventional thermal cycler, which requires 1 hour and 50 minutes.
DESCRIPTION OF REFERENCE NUMERALS
(155) 1: conical tube in which a reaction solution is accommodated 2: heating block maintained at a high temperature 3: blower fan 4: blower nozzle 5: air (artificial airflow) 100: casing 110: lower plate 120: upper plate 122: introduction opening 124: fastener 130: side plate 140: display device 150: holder 152: holding body 154: mounting hole 156: fixing jig 160: hinge 170: signal input device 180: power supply device 200: heating module 210: heater 220: heating block 222: recess 224: light transmitting portion 230: guide unit 232: guide pipe 234: guide beam 236: elastic spring 240: opening and closing block 300: sensing module 310: module housing 312: module cover 314: module base 316: mounting wall 318: through-hole 320: light capturing unit 322: PCB 324: sensor 330: emission filter 400: drive module 410: motor 420: motor shaft 500: cooling module 510: blower fan 520: blower nozzle 522: inlet 524: outlet 600: cover module 610: cover housing 612: housing portion 614: opening and closing cover 620: cover base 622: filter insertion slot 624: light passage 630: light emitting unit 63 2: PCB 634: light source 640: tube cap heating element 642: through-hole 650: excitation filter 700: control device