Abstract:
Provided are a polymerase chain reaction (PCR) module and a PCR system including the same. The PCR module includes: a detachable PCR chip including a PCR chamber unit in which a PCR solution is accommodated; a heater unit for heating the PCR solution in the PCR chip with a preset temperature; a detecting unit for detecting a PCR signal of the PCR solution; a PCR chip installation unit for mounting/detaching the PCR chip using a one-touch method, in which the heater unit is adhered to the PCR chip with a predetermined pressure when mounting the PCR chip and the heater unit is separated from the PCR chip when detaching the PCR chip; and a housing covering at least the heater unit and the detecting unit so that they are not exposed to the outside.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This application claims the priority of Korean Patent Application No. 10-2005-0036687, filed on May 2, 2005 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.  
         [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a polymerase chain reaction (PCR) module and a multiple PCR system having the PCR module, and more particularly, to a PCR module capable of preventing contamination of a detecting unit and a heater unit when installing or removing a PCR chip, and a multiple PCR system including the PCR module.  
         [0004]     2. Description of the Related Art  
         [0005]     Polymerase chain reaction (PCR), which is a technology to amplify DNA copies of specific DNA or RNA fragments in a reaction container, is an epoch-making development in life science technology. In the PCR technology at the beginning, PCR products are separated on a gel and the approximate amount of the PCR products is estimated. Recently, however, co-amplification of different samples at different temperatures has been carried out and precisely monitored in real-time.  
         [0006]      FIG. 1  is a schematic block diagram of a multiple PCR system  1  disclosed in Korean Patent Application No. 10-2004-0102738 filed by the applicant of the present invention on Dec. 8, 2004. In the multiple PCR system  1 , co-amplification of different samples at different temperatures is performed in addition to monitoring the PCR reaction process in real-time, as described above. Referring to  FIG. 1 , the multiple PCR system  1  includes a plurality of PCR modules  40  and a host computer  50 , which controls the PCR modules  40  and collects data. Each of the PCR modules  40  performs a PCR reaction on a single sample at a specific temperature and monitors the process and transmits the monitoring results to the host computer  50  in real-time. Any number of PCR modules  40  can be detachably installed in the PCR system  1  and connected to the host computer  50 .  
         [0000]      50  in real-time. Any number of PCR modules  40  can be detachably installed in the PCR system  1  and connected to the host computer  50 .  
         [0007]     As illustrated in  FIG. 1 , each of the PCR modules  40  includes a detachable microchip-type PCR reaction container (hereinafter referred to as a PCR chip)  10 , a detecting unit  30  that detects a PCR product signal based on the amount of a PCR product of a sample solution (hereinafter referred to as a PCR solution) contained in a PCR reaction chamber (hereinafter referred to as a PCR chamber)  11  of the PCR chip  10  in which a PCR reaction is to occur, and an operation control unit  41  that automatically controls the whole PCR process and transmits and receives data to and from the host computer  50 . The detachable PCR chip  10  can be used once or repeatedly. The PCR chamber  11  in which the PCR solution is accommodated and where the PCR reaction occurs is formed in the PCR chip  10 . The PCR module  40  further includes a heater  20  contacting the bottom surface of the PCR chip  10  and transmitting heat so that the temperature of the PCR chip  10  is maintained at an appropriate temperature. A separate power supply device  51  applies a constant voltage to the heater  20 . In addition, the PCR module  40  may further include a cooling device  43  besides the heater  20  so that the temperature of the PCR solution inside the PCR chip  10  quickly reaches a target temperature.  
         [0008]     The detecting unit  30  in the PCR module  40  includes a light source  31  or an AC power supply unit  33 , and detects a PCR product signal based on the amount of a PCR product. The PCR product signal may be a fluorescent signal emitted from the PCR chamber  11  disposed inside the PCR chip  10 . In this case, the detecting unit  30  includes the light source  31  which emits light onto the PCR solution. After the light is emitted from the light source  31  onto the PCR solution, a fluorescent light emitted from the PCR solution is detected by a detector (not shown). The PCR product signal can also be an electrical signal, in which case the detecting unit  30  includes a sensor (not shown) for detecting the electrical signal. The sensor installed inside the PCR chip  10  senses a PCR product signal generated when an AC current is supplied to the PCR solution and transmits the sensed PCR product signal to the host computer  50 . To do this, the detecting unit  30  includes the AC power supply unit  33  instead of the light source  31 .  
         [0009]     The operation control unit  41 , which transmits and receives data to and from the host computer  50  by automatically controlling the entire PCR process, includes a central processing unit (CPU)  42  composed of a microprocessor, an auxiliary memory device  44 , and a random access memory (RAM)  45 , and controls the PCR process according to a set program. The operation control unit  41  independently controls the detecting unit  30 , the PCR chip  10 , the heater  20 , the cooling device  43 , and the power supply device  51  via a data communication unit (not shown) in real-time. Also, the operation control unit  41  performs a predetermined operation according to the set program or predetermined parameter values set by a user after performing appropriate operations based on information obtained from the sensor adhered to the detecting unit  30 , the PCR chip  10 , the heater  20 , and the cooling device  43  or the data communication unit. For example, according to the PCR process, the temperature of the PCR chamber  11  is appropriately controlled, or operation of the cooling device  43 , the detecting intervals of the detecting unit  30 , etc. can be controlled. In addition, the operation control unit  41  may further include a separate input and output device  46  so that the PCR module  40  can be independently driven.  
         [0010]      FIG. 2  is a schematic perspective view of the multiple PCR system  1  illustrated in  FIG. 1 . As illustrated in  FIG. 2 , the multiple PCR system  1  has a space in which a plurality of modules  40  can be accommodated. A plurality of slots (not shown) are formed in the space in which the PCR modules  40  can be installed, and thus the PCR modules  40  are easily detachable. Also, a display unit  60  which displays data received from the PCR modules  40  and an input unit  70  in which the user inputs required signals are installed in the multiple PCR system  1 .  
         [0011]      FIG. 3  is a perspective view of one of the PCR modules  40 . As illustrated in  FIG. 3 , the PCR module  40  includes a main body  48  and a cover  47  installed on the main body  48  capable of performing a hinge motion. A pin  49  in which a plurality of electrodes are formed is formed on the bottom surface of the main body  48 . The PCR module  40  can be installed in the slot in the PCR system  1  via the pin  49 . When the PCR module  40  uses, for example, a fluorescent signal as the PCR product signal, a detecting unit  30  composed of an optical system including a light source having lenses is installed in the cover  47 . Also, a space for accommodating the PCR chip  10  is formed in a portion of the main body  48  corresponding to the detecting unit  30 , and the heater  20  is installed below the space. In such a structure, if the cover  47  closes by rotating the cover  47  after the PCR chip is placed in the space above the heater  20 , the detecting unit  30  of the cover  47  faces the PCR chamber  11  of the PCR chip  10 , and thus, the fluorescent signal emitted from the PCR solution within the PCR chamber  11  can be detected. As illustrated in  FIG. 4 , the PCR chamber  11  in which the PCR solution is accommodated is formed in the PCR chip  10 , the PCR solution flowing in via an inlet  12  and flowing out via an outlet  13 . Thus, the detecting unit  30  can detect the fluorescent signal emitted from the PCR solution during the PCR reaction.  
         [0012]     However, in the PCR module  40  having the above-described structure, the optical system in the detecting unit  30  is exposed to the outside when mounting the PCR chip  10  in the PCR module  40 , and thus the detecting unit  30  is susceptible to contamination. As a result, the accuracy of measured values is reduced. The heater  20  also gets contaminated when installing the PCR chip  10 , thereby making it difficult to appropriately adjust the temperature of the PCR solution inside the PCR chip  10 . In addition, because the user places the PCR chip  10  on top of the heater  20 , the heater  20  and the PCR chip  10  can get damaged due to carelessness and it is difficult to adhere the heater  20  and the PCR chip  10  with the optimum pressure. Furthermore, it is inconvenient for the user to use since the cover  47  of the PCR module  40  needs to be opened and closed whenever installing or removing the PCR chip  10 .  
       SUMMARY OF THE INVENTION  
       [0013]     The present invention provides a polymerase chain reaction (PCR) module capable of preventing contamination of a detecting unit and a heater unit when installing or removing a PCR chip, and a multiple PCR system including the PCR module.  
         [0014]     The present invention also provides a PCR module that is easily mountable or detachable with one touch, and a multiple PCR system including the PCR module.  
         [0015]     The present invention also provides a PCR module that is structured so that a heater and the PCR chip can be optimally adhered to each other, and a multiple PCR system including the PCR module.  
         [0016]     According to an aspect of the present invention, there is provided a PCR module, including: a detachable PCR chip including a PCR chamber unit in which a PCR solution is accommodated; a heater unit for heating the PCR solution in the PCR chip with a preset temperature; a detecting unit for detecting a PCR signal of the PCR solution; a PCR chip installation unit for mounting/detaching the PCR chip using a one-touch method, in which the heater unit is adhered to the PCR chip with a predetermined pressure when mounting the PCR chip and the heater unit is separated from the PCR chip when detaching the PCR chip; and a housing covering at least the heater unit and the detecting unit so that they are not exposed to the outside.  
         [0017]     The PCR chip installation unit may include: a heater mounting guide for adhering the heater unit to the PCR chip with a predetermined pressure when mounting the PCR chip; a push rod which enables the PCR chip to be mounted by locking the heater mounting guide when the PCR chip is not yet mounted, and enables the heater mounting guide to adhere the heater unit to the PCR chip by releasing the heater mounting guide when mounting the PCR chip; and a detaching button to draw back the heater unit to separate the heater unit from the PCR chip when detaching the PCR chip. The heater mounting guide may have a link structure in which respective ends of the heater mounting guide are rotatably coupled to the heater unit and the housing.  
         [0018]     The heater unit may be elastically biased towards the PCR chip by a spring.  
         [0019]     The push rod may be elastically biased towards the heater mounting guide by a spring, and a first end of the push rod may push and lock the heater mounting guide when the PCR chip is not yet mounted. The first end of the push rod locking the heater mounting guide may be slanted, and the slanted surface may push the heater mounting guide when the PCR chip is not yet mounted. Also, a protrusion may be formed on a side of the push rod so that the protrusion can contact the bottom of the PCR chip when the PCR chip is being mounted. When mounting the PCR chip, the bottom of the PCR chip may be hooked by the protrusion of the push rod and the push rod may retreat from the heater mounting guide, thereby releasing the locked heater mounting guide.  
         [0020]     The PCR chip installation unit further include an installation detecting sensor for detecting whether or not the PCR chip is mounted. For example, the installation detecting sensor may be a switch that is turned “on” by being pushed by a second end of the push rod when mounting the PCR chip and is turned “off” when the PCR chip is detached.  
         [0021]     The PCR chip installation unit may further include: a cover encompassing the heater unit and the heater mounting guide to provide a safe movement path for the PCR chip when mounting or detaching the PCR chip and to protect the PCR chip; and a flat chip guide disposed between the cover and the heater unit to form the movement path for the PCR chip together with the cover. A curved protrusion corresponding to the width and height of the PCR chip may be formed in the center of the cover. In this case, the PCR chip may move between the curved protrusion of the cover and the chip guide. An aperture is formed in the chip guide so that the PCR chip disposed at the front of the chip guide and the heater unit disposed at the rear of the chip guide can adhere to each other when mounting the PCR chip.  
         [0022]     Also, a window may be formed in a part of the cover facing the PCR chamber unit of the PCR chip mounted inside the PCR module. Then, light emitted from the detecting unit is incident on the PCR solution in the PCR chamber unit via the window, and fluorescent signals generated from the PCR solution may be transmitted to the detecting unit via the window.  
         [0023]     The heater unit may include: a heater plate for heating the PCR chip by directly contacting the PCR chip; a substrate in which a circuit for setting a temperature of the heater plate to a preset temperature is installed; a substrate holder for fixing the substrate; and electrodes formed between the substrate and the heater plate to transmit current from the substrate to the heater plate. Also, the heater unit may further include a heater plate guide for fixing the electrodes and the heater plate together by encompassing the circumference of the electrodes and a top surface of the heater plate. The electrodes may prevent poor connection by being elastically biased towards the heater plate via a spring, and ends of the electrodes contacting the heater plate being flat. Also, a shaft is formed in a protrusion on both sides of the substrate holder so that the heater mounting guide can be rotatably coupled.  
         [0024]     According to another aspect of the present invention, there is provided a PCR system including: the PCR module described above; and a host computer which controls the PCR module and collects data. Any number of PCR modules can be detachably installed. The PCR system can simultaneously cause PCR reaction to different PCR solutions at different temperatures using multiple PCR modules in addition to monitoring multiple PCR reaction processes in real-time via the host computer. Also, the PCR system may further include a plurality of slots for mounting at least one PCR module, and a pin in which electrodes are formed protrudes from a bottom of each of the PCR modules so that the PCR modules can be mounted in the slots.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]     The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:  
         [0026]      FIG. 1  is a schematic block diagram of a prior multiple polymerase chain reaction (PCR) system;  
         [0027]      FIG. 2  is a schematic perspective view of the multiple PCR system illustrated in  FIG. 1 ;  
         [0028]      FIG. 3  is a perspective view of a prior PCR module installed in the multiple PCR system illustrated in  FIG. 1 ;  
         [0029]      FIG. 4  is a plan view of a prior PCR chip installed in the PCR module illustrated in  FIG. 3 ;  
         [0030]      FIGS. 5A and 5B  are perspective views of a PCR module according to an embodiment of the present invention;  
         [0031]      FIG. 6  is a diagram illustrating the inner structure of the PCR module illustrated in  FIGS. 5A and 5B ;  
         [0032]      FIG. 7  is a diagram illustrating the inner structure of the PCR module illustrated in  FIG. 6  from which a detecting unit is removed;  
         [0033]      FIGS. 8A and 8B  are exemplary views of a PCR chip installation unit according to an embodiment of the present invention;  
         [0034]      FIGS. 9A through 9C  are diagrams for illustrating operations of the PCR chip installation unit illustrated in  FIGS. 8A and 8B ;  
         [0035]      FIGS. 10A and 10B  are a perspective view and a cross sectional view of a heater unit according to an embodiment of the present invention;  
         [0036]      FIG. 11  is a perspective view of the structure of a PCR chip according to an embodiment of the present invention;  
         [0037]      FIG. 12  is a schematic plan view of multiple PCR chambers included in the PCR chip illustrated in  FIGS. 5A and 5B ;  
         [0038]      FIGS. 13A and 13B  are front and rear perspective views of a heater-plate cleaning chip according to an embodiment of the present invention; and  
         [0039]      FIG. 14  is a perspective view of a temperature calibration chip of a heater unit according to an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0040]     The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.  
         [0041]      FIGS. 5A and 5B  are perspective views of a PCR module  100  according to an embodiment of the present invention. Referring to  FIG. 5A , both a detecting unit  110  (see  FIG. 6 ) and a heater unit  230  (see  FIG. 8B ) are installed inside the PCR module  100  unlike a prior PCR module. Also, a PCR chip  300  can be installed with a single touch via an inserting slot  105  formed on top of the PCR module  100 . Therefore, there is less possibility of a user causing damage when installing the PCR chip  100  because the detecting unit  110  and the heater unit  230  are not exposed to the outside.  FIG. 5B  is a view of the PCR module  100  in which the PCR chip  300  is installed. The PCR chip  300  can be detached from the PCR module  100  when a detaching button  210  is pressed. Therefore, the present invention contains improvement to parts of a prior PCR system  1  illustrated in  FIG. 1  indicated by dotted-lined rectangles.  
         [0042]      FIG. 6  is a diagram illustrating the inner structure of the PCR module  100  illustrated in  FIGS. 5A and 5B . As illustrated in  FIG. 6 , the detecting unit  110 , an operation control unit  120 , and a PCR chip installation unit  200  are installed inside a housing  101  of the PCR module  100 . The operation control unit  120  has the same function and structure as an operation control unit  41  of the prior PCR system  1 . That is, the operation control unit  120  has a structure in which a central processing unit (CPU), an auxiliary device, etc. are mounted on a PCB circuit, and controls the PCR process according to a set program. In addition, a pin  122  in which electrodes are formed protrudes downwards from the housing  101  so that the PCR module  100  can be installed in a slot formed in a PCR system.  
         [0043]     The detecting unit  110  illustrated as an example in  FIG. 6  uses a fluorescent signal emitted from a PCR solution inside a PCR chamber (see  FIG. 12 ) as a PCR product signal. Therefore, although not illustrated in  FIG. 6 , the detecting unit  110  includes a light source disposed to face the PCR chamber inside the PCR chip  300  and an optical system which condenses the fluorescent signal. The fluorescent signal is, for example, transmitted to a plurality of optical detectors  114  via a light transmitting element  112 . The optical detectors  114  may be photodiodes, photo multiplier tubes (PMT), charge coupled devices (CCDs), etc. The optical detectors  114  measure the size of the fluorescent signal and transmit the result to the operation control unit  120 . Thereafter, the operation control unit  120  analyzes the PCR reaction of the PCR solution based on the size of the fluorescent signal and transmits the results to the PCR system. Similar to the prior PCR system  1 , the PCR signal may be an electrical signal in which case the detecting unit  110  includes sensors (not shown) to detect the electrical signal instead of the optical detectors  114  and includes an AC power supply unit instead of the light source.  
         [0044]      FIG. 7  is a diagram illustrating the inner structure of the PCR module  100  from which the detecting unit  110  is removed, including a cooling fan  130 , a blast pipe  135 , and the PCR chip installation unit  200 . The purpose of the cooling fan  130  and the blast pipe  135  is to enable the temperature of the PCR solution inside the PCR chip  300  to quickly reach a target temperature as in the prior art. The PCR chip installation unit  200  enables the PCR chip  300  to be safely installed and removed from the PCR module  100 , and applies the PCR chip  300  installed inside the PCR module  100  to the heater unit  230  with a pressure of, for example, about 20-30 psi. The PCR chip  300  can be installed and/or removed from the PCR module  100  without exposing the detecting unit  110  and the heater unit  230  to the outside by using the PCR chip installation unit  200  according to the current embodiment of the present invention.  
         [0045]      FIGS. 8A and 8B  are exemplary views of the PCR chip installation unit  200  according to an embodiment of the present invention.  FIG. 8A  is a front perspective view of the PCR chip installation unit  200  and  FIG. 8B  is an exploded perspective view of the PCR chip installation unit  200 . In  FIG. 8A , a cover  220  is illustrated which provides a safe movement path for the PCR chip  300  when installing and/or removing the PCR chip  300  and protects the installed PCR chip  300 . However, in  FIG. 8B , the cover  220  is not illustrated for convenience of explanation. Referring to  FIGS. 8A and 8B , the PCR chip installation unit  200  includes the cover  220 , a push rod  211 , an installation detecting sensor  213 , a heater mounting guide  214 , a chip guide  216 , and the detaching button  210 .  
         [0046]     As illustrated in  FIG. 8A , the cover  220  surrounds the heater unit  230  and the heater mounting guide  214 . A curved protrusion corresponding to the width and height of the PCR chip  300  is formed in the center of the cover  220 . Therefore, the cover  220  forms a movement path of the PCR chip  300  together with the flat chip guide  216 . In other words, the PCR chip  300  is inserted between the protrusion of the cover  220  and the chip guide  216 . Also, a window  225  is formed in the cover  220  so that the PCR chamber inside the PCR chip  300  can be seen when the PCR chip  300  is inserted. Therefore, the light emitted from the light source of the detecting unit  110  can be incident on the PCR solution inside the PCR chamber via the window  225 , and the fluorescent light emitted from the PCR solution can also be incident on the optical system of the detecting unit  110  via the window  225 .  
         [0047]     Meanwhile, the push rod  211  locks the heater mounting guide  214  when the PCR chip  300  is not yet inserted, and when the PCR chip is inserted, releases the heater mounting guide  214 . Thus, the push rod  211  applies the heater unit  230  to the PCR chip  300 . A protrusion  211   a  is formed on the push rod  211  so that the bottom portion of the PCR chip  300  is hooked by the protrusion  211   a  when inserting the PCR chip  300 . Therefore, the push rod  211  is pushed downwards by the PCR chip  300  when inserting the PCR chip  300 , and the push rod  211  is elevated by the recovery force of a spring  212  when removing the PCR chip  300 . The purpose of the installation detecting sensor  213  is to notify the operation control unit  120  of whether or not the PCR chip  300  is inserted, and can be configured in a simple switch. For example, when the switch is turned “on” by the downward motion of the push rod  211 , it means that the PCR chip  300  is inserted. Conversely, when the switch is turned “off” by the upward motion of the push rod  211 , it means that the PCR chip  300  is removed.  
         [0048]     The purpose of the heater mounting guide  214  is to apply the heater unit  230  to the PCR chip  300  with an appropriate pressure. As illustrated in  FIG. 8B , the heater mounting guide  214  has a link structure. That is, both ends of the heater mounting guide  214  are each rotatably coupled to the heater unit  230  and the housing  101 . In such a structure, the heater mounting guide  214  is locked by the push rod  211  when the PCR chip  300  is not inserted, and when the heater mounting guide  214  is released by the downward motion of the push rod  211 , the heater unit  230  is applied to the PCR chip  300  by the force of the spring  215 . The purpose of the detaching button  210  is to draw back the heater mounting guide  214  so that the heater unit  230  separates from the PCR chip  300 .  
         [0049]     The operation of the PCR chip installation unit  200  will be described in detail with reference to  FIGS. 9A through 9C .  
         [0050]      FIG. 9A  is a side view of the PCR chip installation unit  200  when the PCR chip  300  is not inserted. The cover  220  is omitted in  FIG. 9A . As illustrated in  FIG. 9 , the push rod  211  is elastically biased towards the heater mounting guide  214  due to the elastic force of the spring  212 . Also, an end of the push rod  211  towards the heater mounting guide  214  is slanted. The slanted end of the push rod  211  pushes the heater mounting guide  214 , and thus the heater unit  230  connected to the heater mounting guide  214  in the link structure is separated and drawn back from the chip guide  216 .  
         [0051]      FIG. 9B  is a side view of the PCR chip installation unit  200  in which the PCR chip  300  is inserted. When the PCR chip  300  is inserted between the curved protrusion (see  FIG. 8A ) of the cover  220  and the chip guide  216 , the bottom portion of the PCR chip  300  is hooked by the protrusion  211   a  formed on the push rod  211 , and thus the push rod  211  descends. The installation detecting sensor  213  is disposed on the bottom of the push rod  211 . Therefore, when the PCR chip  300  is inserted, the switch of the installation detecting sensor  213  is pushed by the bottom portion of the push rod  211  and is turned “on,” thereby notifying the operation control unit  120  that the PCR chip  300  is inserted. Meanwhile, the heater mounting guide  214  is separated from the slanted end of the push rod  211  when the push rod  211  descends. As a result, the heater unit  230  is applied to the PCR chip  300  as the heater unit  230  is pushed by the elastic force of the spring  215 . That is, when the PCR chip  300  is inserted in a direction illustrated by an arrow A 1 , the push rod  211  moves in a direction illustrated by an arrow A 2  and the heater unit  230  moves in a direction indicated by an arrow A 3 . An aperture  219  (see  FIG. 8B ) must be formed in the chip guide  216  so that the PCR chip  300  located at the front of the chip guide  216  and the heater unit  230  located at the rear of the chip guide  216  can adhere to each other.  
         [0052]      FIG. 9C  is a side view of the PCR chip  300  illustrating a removal operation of the PCR chip  300 . When wishing to remove the PCR chip  300 , the detaching button  210  above the heater mounting guide  214  is pressed in a direction indicated by an arrow A 4 . Then, the heater mounting guide  214  in the link structure is pushed by the detaching button  210  and rotates. Accordingly, the heater unit  230  connected to the heater mounting guide  214  separates from the PCR chip  300  and retreats in a direction indicated by an arrow A 5 . Simultaneously, the push rod  211  ascends in the direction indicated by an arrow A 6  due to the recovery force of the spring  212 , and thus the PCR chip  300  separates from the PCR chip installation unit  200  and ascends.  
         [0053]      FIGS. 10A and 10B  are detailed views of the heater unit  230 .  FIG. 10A  is a perspective view of the heater unit  230  and  FIG. 10B  is a cross sectional view of the heater unit  230 . Referring to  FIGS. 10A and 10B , the heater unit  230  includes a heater plate  235  which heats the PCR chip  300  by directly contacting the PCR chip  300 , a PCB substrate  236  on which a control circuit for controlling the temperature of the heater plate  235  to a preset temperature is mounted, a PCB holder  231  to which the PCB substrate  236  is fixed, and an electrode  237  vertically formed between the PCB substrate  236  and the heater plate  235  to transmit current from the PCB substrate  236  to the heater plate  235 . The electrode  237  and the heater plate  235  can be fixed to each other by a heater plate guide  233  encompassing the circumference of the electrode  237  and the top of the heater plate  235 . Also, the electrode  237  may prevent unstable supply of current due to poor contact caused by, for example, the vibration of the PCR module  100  by adhering the electrode  237  to the heater plate  235  using, for example, a spring. Furthermore, a contact surface of the electrode  237  and the heater plate  235  may be maximized by making the end of the electrode  237  contacting the heater plate  235  as flat as possible. Two shafts  232  are respectively formed on both sides of the PCB holder  231  so that the heater mounting guide  214  can be connected in a link structure. The heater mounting guide  214  may be rotatably coupled to the heater unit  230  via the shafts  232 .  
         [0054]     As described above, in the case of the prior PCR module, a user installed a PCR chip by opening a cover of the PCR module, personally placing the PCR chip on top of a heater inside the PCR module, and then closing the cover. Thus, a relatively small-sized PCR chip was manufactured since the PCR chip needs to be completely inserted into the PCR module. As a result, it is difficult for the user to handle the PCR chip, and there is a possibility of contaminating a PCR solution inside the PCR chip due to carelessness. However, in the case of the present invention, the PCR chip  300  can be installed by a one-touch operation from the outside of the PCR module  100  via the inserting slot  105  as illustrated in  FIG. 5A , and thus a relatively large PCR chip  300  can be manufactured.  FIG. 11  is an exemplary perspective view of the structure of the PCR chip  300 . As illustrated in  FIG. 11 , the PCR chip  300  includes a multiple PCR chambers  310  in which a PCR reaction occurs and is formed on a substrate made of, for example, plastic, and a round handle  320  is formed at one end of the PCR chip  300  so that it is convenient for the user to handle the PCR chip  300 . The user holds the PCR chip  300  by the handle  320  and vertically inserts the PCR chip  300  into the inserting slot  105  of the PCR module  100 , thereby installing the PCR chip  300  in multiple PCR modules  100 .  
         [0055]      FIG. 12  is an exemplary schematic plan view of the multiple PCR chambers  310  included in the PCR chip  300 . In the case of a prior PCR chip illustrated in  FIG. 4 , a single chamber is included in a single PCR chip. However, the PCR chip  300  according to the present invention can have a multiple chamber structure in which a plurality of chambers are included in a single PCR chip, as illustrated in  FIG. 12 . Therefore, it is possible to observe a PCR reaction of a number of samples at once. First through fourth chambers  311   a  through  311   d  are illustrated in  FIG. 14  as an example. Referring to  FIG. 12 , the first through fourth chambers  311   a  through  311   d  are formed side by side on a substrate  315  made of silicon, glass, or plastic, and inlets  312   a  through  312   d  and outlets  313   a  through  313   d  are respectively connected to each of the first through fourth chambers  311   a  through  311   d . Also, a barrier rib  314  may be further formed on both sides of each of the first through fourth chambers  311   a  through  311   d  to separate fluorescent signals generated from adjacent chambers. The fluorescent signals generated from each of the first through fourth chambers  311   a  through  311   d  are transmitted to the four optical detectors  114  via the four light transmitting elements  112  such as optical fibers illustrated in  FIG. 6 . A number of structures of an optical system to transmit a plurality of fluorescent signals generated from multiple chambers to optical detectors via separate light transmitting elements are disclosed. Thus, their descriptions will be omitted.  
         [0056]     Meanwhile, in the case of the PCR module  100  of the present invention, the heater unit  230  is not exposed to the outside without dismantling the housing  101  of the PCR module  100 , and thus it may be difficult to remove contamination from the heater plate  235  or to periodically clean the heater plate  235 . As a result, a cleaning chip having a similar structure to the PCR chip  300  may be used to clean the heater plate  235 .  FIGS. 13A and 13B  are front and rear perspective views of a heater-plate cleaning chip  330 . As illustrated in  FIGS. 13A and 13B , the heater-plate cleaning chip  330  includes a stick  332  that can move up and down mounted in a plastic substrate having a similar shape to the PCR chip  300 . A top portion of the stick  332  is exposed to the outside even when the heater-plate cleaning chip  330  is completed inserted in the PCR module  100 . Therefore, the user can move the stick  332  up and down by holding the top portion of the stick  332 . Also, as illustrated in  FIG. 13B , a cleaner  335  to clean the heater plate  235  is formed on a rear surface of the stick  332  which contacts the heater plate  235 .  
         [0057]     In addition, in order for the optimum PCR reaction to occur, the heater unit  230  must accurately heat the PCR chip  300  with a preset temperature. Thus, the heater unit  230  should be constantly checked to determine if it is accurately operating. To do this, a temperature-adjusting chip having a similar shape to the PCR chip  300  on which a temperature sensor is formed can be produced, as in the case of the heater-plate cleaning chip  330 .  FIG. 14  is a perspective view of a temperature-adjusting chip  350  of the heater unit  230 . As illustrated in  FIG. 14 , the temperature-adjusting chip  350  is structured to include a temperature sensing unit  353  in a plastic substrate having a similar shape to the PCR chip  300 . A temperature sensor such as a thermocouple is mounted on a substrate made of, for example, plastic, glass, or silicon and installed in the temperature sensing unit  353 . Therefore, the heater plate  235  adheres to the temperature sensing unit  353  when the temperature-adjusting chip  350  is installed in the PCR module  100 . The temperature sensing unit  353  converts the temperature of the heater plate  235  into electrical signals and the electrical signals generated in the temperature sensing unit  353  are transmitted via wires  352 . Thus, the temperature of the heater plate  235  can be simply measured from the outside.  
         [0058]     Up to now, the structure and operation of the PCR module  100  according to an embodiment of the present invention has been explained. Any number of the above-described PCR modules  100  can be detachably installed in a PCR system illustrated in  FIGS. 1 and 2  and be connected to a host computer  50  of the PCR system  1 . That is, any number of PCR modules  100  can be installed in slots (not shown) in the PCR system  1  via a pin  122  protruding from each of the bottom of the PCR modules  100 . Therefore, the PCR modules  100  of the present invention are installed in the PCR system  1  using the same prior method and operate in the same manner.  
         [0059]     According to the present invention described above, a detecting unit and a heater unit installed in a PCR module are not exposed to the outside. Thus, damage to or contamination of the detecting unit or the heater unit when installing or removing a PCR chip can be prevented. In addition, according to the present invention, a user can easily install and remove the PCR chip in with one-touch, thereby making it convenient for the user to use, and there is less possibility of contaminating a PCR solution when installing the PCR chip in the PCR module due to carelessness. Furthermore, according to the present invention, a heater plate and the PCR chip are adhered to each other with optimum pressure, and thus a PCR reaction can occur at an optimum temperature.  
         [0060]     Also, cleaning of the heater plate and adjusting the temperature of the heater plate can be performed by a simple method.  
         [0061]     While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.