Abstract:
An auto microfluidic hybridization chip platform is disclosed to provide a hybrid reaction test system with the features of fast reactions, automatic operations, and a convenient platform. The platform includes a flow control system with a platform base, a microfluidic hybridization chip, a microfluidic hybridization chip support, a test agent support of the microfluidic hybridization chip; and a signal detection system. Using a microfluidic pipeline to connect various parts does not only realize automation and a small volume, but also increases the reaction speed.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of Invention  
           [0002]    The invention relates to an auto microfluidic hybridization chip platform used for nucleic-acid hybridization reaction tests of samples.  
           [0003]    2. Related Art  
           [0004]    In recent years, molecular biology has made tremendous progress in its technology. For example, techniques such as PCR and nucleic-acid hybridization have been integrated with material sciences, bio-informatics, and electronic technology. This creates the new scope of biochips. In particular, the nucleic-acid hybridization reaction is a necessary and key procedure in the test procedures of molecular biology. The conventional nucleic acid hybridization procedure is complicated and time-consuming, which makes it the bottleneck step of the whole test. In general, hybridization reactions take about 4 to 12 hours. If one can simplify the operation and reaction time, the test can be introduced to usual point-of-care or home-care purposes. It will be the optimized solution for people being tested.  
           [0005]    With complicated and time-consuming operation procedures, the conventional hybridization reactions require the uses of a hybridization box, a rotator, a vortex vibrator, and a scanning identification machine that cost a lot of money. Although there are already many international manufacturers in Europe, America, and Japan that apply automation technology to hybridization platforms requiring less manpower in place of the hybridization box, their specification still uses slides and cannot achieve the goal of mass filtering. For example, the products of Biogem, Genomic, PerkinElmer lifesciences, and Tecan all use such designs. The design disclosed in the U.S. Pat. No. 6,238,910 has the advantage that the hybridization chamber can accommodate two different sizes of slides. However, its drawback is also that the pipeline is exposed to the environment, inconvenient in operations.  
           [0006]    The hybrid reaction platforms currently available on the market are designed according to the glass specification. The products are mainly for molecular biology laboratories, drug research and development institutes, and medical test centers. Most of them use high-density micro array probes. Moreover, due to their higher costs, such products are not popular in disease detection.  
         SUMMARY OF THE INVENTION  
         [0007]    In view of the foregoing, the invention provides an auto microfluidic hybridization chip platform. It is designed to use a microfluidic chip within which all hybridization processes are completed. The size of the chip is about that of normal slides. The advantages of the micro fluid chip are its convenience and disposability.  
           [0008]    The disclosed auto microfluidic hybridization chip platform includes a test agent support, a fluid control system and a microfluidic hybridization chip. The test agent support holds at least one test agent bottle containing a test agent. The test agent bottle is connected to the fluid control system and then to the microfluidic hybridization chip via a thin pipe and a connector. The fluid control system has at least a micro tunnel powered by air to control whether the test agent should flow through the micro tunnel to the microfluidic hybridization chip.  
           [0009]    The microfluidic hybridization chip contains a sample receiving region, a mixing and denature region, and a hybridization and test region. The sample receiving region directly receives external samples. The fluid control system pushes the necessary test agents and samples to the mixing and denature region. Through the meander path of the mixing and denature region, the samples and test agents are fully mixed and denatured. Afterwards, the mixture enters the hybridization and test region.  
           [0010]    Using such a platform, the devices required in the prior art (such as hybridization box, rotator, vortex vibrator, and scanning identification machine) are avoided. The operation procedure is simplified and the reaction time is reduced. Therefore, the invention can be popularized to point-of-care or home-care purposes. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    The invention will become more fully understood from the detailed description given hereinbelow illustration only, and thus are not limitative of the present invention, and wherein:  
         [0012]    [0012]FIG. 1 is a schematic view of the appearance of the invention;  
         [0013]    [0013]FIG. 2 is a schematic view of the invention;  
         [0014]    [0014]FIG. 3 is an exploded view of the disclosed microfluidic hybridization chip support;  
         [0015]    [0015]FIG. 4 is a schematic view of the microfluidic hybridization chip combined with the microfluidic hybridization chip support;  
         [0016]    [0016]FIG. 5 is a schematic view of the elastic sleeve ring;  
         [0017]    [0017]FIG. 6 is an exploded diagram of the microfluidic hybridization chip;  
         [0018]    [0018]FIG. 7 is a top view of the microfluidic hybridization chip;  
         [0019]    [0019]FIG. 8 is a schematic view of the flow control system;  
         [0020]    [0020]FIG. 9 is a schematic view of the flow transmission module;  
         [0021]    [0021]FIG. 10 is a schematic view of the test agent support; and  
         [0022]    [0022]FIG. 11 is a schematic view of the signal detection system. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]    With reference to FIG. 1, the disclosed auto microfluidic hybridization platform is covered by a case  100 . One side of the case  10  is designed for the insertion of a microfluidic hybridization chip  20 . That is, the invention is designed to be modularized according to different sample requirements. The top has a viewing window  11  formed from a transparent material and a control panel  12 . One can check the reaction process and result via the viewing window  11  and put all control interfaces in the control panel  12 . The internal structure is shown in FIG. 2. It includes a platform base  30 , a microfluidic hybridization chip  20 , a microfluidic hybridization chip support  60 , a flow control system  50  of the microfluidic hybridization chip, a test agent support  40  of the microfluidic hybridization chip, and a signal detection system (see FIG. 11). The platform base  30  provides the functions of support. We describe the functions and structure of the rest parts in the following paragraphs.  
         [0024]    As shown in FIG. 3, the microfluidic hybridization chip support  60  is comprised of an upper cover  61  and a lower cover  62 . It is used to support the microfluidic hybridization chip  20 , which is fixed by several screws  622  penetrating through holes  621 . On the other hand, the lower cover  62  has concaves  624 ,  625  for accommodating heating plates. These heat areas are designed for the microfluidic hybridization chip and will be explained in detail later. As shown in FIG. 4, the function of the upper cover  61  is to put the microfluidic hybridization chip  20  at a fixed position. The thin pipes  612  are the tunnels for the test agent to enter the microfluidic hybridization chip  20 . The thin pipes  612  are fixed onto the upper cover  61  of the support module using ferrules  611  and screws. When the screws are driven in, the ferrules  611  tightly press the thin pipes  612 . After the insertion of the microfluidic hybridization chip  20 , it is fixed using positioning pins  613  along with the positioning holes  211  and the sliding track  212  on the chip. The front end of the microfluidic hybridization chip  20  has a slant angle for the user to insert the microfluidic hybridization chip support  60 . Each positioning pin  613  goes through the corresponding hole  616  on the upper cover  61 , with a spring  614  installed behind for pushing the positioning pin  613  outward. Its back is fixed using a screw  615 . There are several positioning pins  613  in the drawing. They all have exactly the same structure and function. When the microfluidic hybridization chip  20  is inserted into the accommodation space  619  of the microfluidic hybridization chip support  60 , the positioning pins  613  on both sides of the upper cover  61  push against the sliding tracks  212  of the microfluidic hybridization chip  20  (see FIG. 6) so that the microfluidic hybridization chip  20  does not move vertically. One can conveniently push the microfluidic hybridization chip  20  to the end. The bottom of the microfluidic hybridization chip support  60  has a sliding block combined with several springs  618 . The sliding block  617  has corresponding holes  6171  for the thin pipes  612  to plug in. When the microfluidic hybridization chip  20  is pushed to the end, it depresses the springs  618  behind the sliding block  617  (FIG. 4). When the pushing force is removed, the microfluidic hybridization chip  20  is moved outward under the spring force of the springs  618 . The positioning holes  211  on the microfluidic hybridization chip  20  arethen shifted to one of the positioning pins  613 . Due to the spring force of the springs  614 , the positioning pins  613  are pushed outward, inserting into the positioning holes  211  of the microfluidic hybridization chip  20 . The microfluidic hybridization chip  20  is thus fixed here. After the test, one only needs to pull the microfluidic hybridization chip  20  out lightly to dismount the micro fluid hybridization chip  20 . This kind of positioning means does not require complicated structural designs but achieves a high precision.  
         [0025]    The connection between the tunnel inlet/outlet at the front end of the microfluidic hybridization chip  20  and the thin pipe  612  is sealed using an elastic sleeve ring  81 . As shown in FIG. 5, after the microfluidic hybridization chip  20  is inserted into the microfluidic hybridization chip support  60 , it depresses the springs  618  behind the sliding block  617 . Once the pushing force is removed, the microfluidic hybridization chip  20  moves outward under the force of the springs  618 . The micro fluid hybridization chip  20  is then fixed here. Depressing the springs  618  can push the sliding block  617 , pressing the sliding block  617  tightly against the microfluidic hybridization chip  20 . The elastic sleeve ring  81  is also depressed so that the connection between the tunnel inlet/outlet at the front end of the microfluidic hybridization chip  20  and the thin pipe  612  is sealed. Such a connection for different tunnels is simple, convenient, and cheap.  
         [0026]    With reference to FIG. 6, the microfluidic hybridization chip  20  is designed to have a multiple-layer structure, mainly containing an upper cover  21 , a tunnel layer  22 , and a lower cover  23 . The material of the microfluidic hybridization chip  20  can be selected from polymers (PMMA, PET, PDMS, PVC, PS, PC, and so on) and glasses. The upper cover  21  is formed with the positioning holes  211 , the sliding tracks  212 , and the sample inlet/outlet  213 . It along with the lower cover  23  sandwiches the tunnel layer  22 . The tunnel layer  22  can be designed to have a multiple-layer structure too for providing microfluidic tunnels and reactions. The tunnel layer  22  includes a sample receiving region  221 , a mixing and denature region  222 , a hybridization and testing region  223 , a waste solution region  224 , and heat insulating regions  225 ,  226 ,  227  (see FIG. 8). Such a multiple-layer design of microfluidic hybridization chip  20  can have several layers to satisfy various kinds of needs. The manufacturing method is to make each layer separately and then to combine them using bonding techniques (such as thermal bonding). The multiple-layer structure can be formed by injection molding to directly form the micro tunnel on the lower cover.  
         [0027]    The flow control system  50  of the microfluidic hybridization chip contains a control circuit  53 , a driving pump  52 , and a micro flow transmission module  51 . The control circuit  53  controls the driving pump  52  and the micro flow transmission module  51  for controlling the fluid in and out of the microfluidic hybridization chip  20 . The driving pump  52  is mainly used as the power source of transporting the fluid. It can be an injection pump, pneumatic pump, a thermol actuated pump, and a piezoelectric pump and so on. The main functions of the flow transmission module  51  are to send the test agent inside the test agent support  40  into the microfluidic hybridization chip  20  and to send the reacted waste solution to a waste pipe. The reaction test agent flow required during the hybridization is totally controlled by the flow transmission module  51 . Its main structure is shown in FIG. 9. It includes a flow switch valve  511 , a flow transmission module upper cover  512 , a thin pipe module  513 , and a flow transmission lower cover  514 . The upper cover  512  and the lower cover  514  are fixed using screws (not shown). The front end of the lower cover  514  is installed with three elastic sleeve rings  81  for sealing the thin pipes  612  of the microfluidic hybridization chip support  60  and the flow transmission module  51 . The sealing principle and means are similar to those mentioned before. The connection between the driving pump  52  and the flow transmission module  51  is also secured using thin pipes  516  with plastic sleeve rings. Moreover, the connection between the flow transmission module  51  and the test agent support  40  is achieved in the same way, installing a thin pipe on a fixing block to form a thin pipe module  513 . Therefore, the driving pump  52  controls the in and out of the fluid via the flow switch valve  511 . In this manner, the test agent support  40  and the flow transmission module  51  are connected to the microfluidic hybridization chip  20  via the micro tunnel  515 .  
         [0028]    The test agent support  40  contains a base  404 , which is connected to a soft tube  405  using a connection pipe  403 . It also supports several test agent bottles  401  and a waste solution bottle  402 . When the support is inserted into the platform base  30 , its fixing method is using positioning pins along with the positioning holes and sliding tracks on the base as described above. The test agent support  40  also includes a support upper cover to prevent dusts from entering the test agent storage area (FIG. 2).  
         [0029]    After the test sample is dropped into the sample receiving region  221  through the sample inlet/outlet  213 , a tape is used to seal the sample inlet/outlet  213 . The microfluidic hybridization chip  20  is then inserted into the microfluidic hybridization chip support  60 . At the moment, the driving pump  52  starts to drag the sample into the mixing and denature region  222 . Due to the long and meander design of the mixing and denature region  222 , the sample and the test agent can be fully mixed. Once the denature is completed, the sample solution is directed to the hybridization and test region  223 . When the sample solution reaches the hybridization and test region  223 , the driving pump  52  keeps performing the pumping and pushing actions to facilitate the hybridization reactions. At this moment, one can control to have some mixed solution flow into the mixing and denature region  222 , allowing yet hybridized double-helix DNA&#39;s to denature. Finally, the denature DNA are sent back to the hybridization and test region  223  for further hybridization. Such processes are continued for several times until full hybridization is achieved. To facilitate the hybridization efficiency, the hybridization and test region  223  is installed with a micro vibrator (not shown) to enhance the reaction rate. The heating plate concaves  624 ,  625  are also installed with heaters to heat up the hybridization and test region  223  and the mixing and denature region  222 . They can be controlled by a contact pad  623  that is in electrical communications with the microfluidic hybridization chip  20 . To ensure that heat is not released to other areas, heat-insulating areas  225 ,  226 ,  227  are designed on both sides to avoid heat from leaking. The heat-insulating areas  225 ,  226 ,  227  can be formed by forming several vacant regions in the tunnel layer  22  or filling heat-insulating materials therein.  
         [0030]    After the reaction is completed, a signal detection system is used for tests. Such a system can be a fluorescence detection system. As shown in FIG. 11, a light source  71  along with a beam splitter  73  and an object lens  72  excites fluorescent dye molecules on a probe to radiate a fluorescent signal. The fluorescent signal passes through a filter  74  to get rid of unnecessary noise light. The filter light is received by a photo receiver  75 , which then sends it to a signal processing system  76 . The light source  71  can be a LED, laser or a mercury light bulb. It is mainly used to excite the fluorescent dye molecules on the probe. The photo receiver  75  can be a charge coupled device (CCD) or a photo multiplier tube (PMT). The disclosed signal detection system can be directly installed the platform to perform direct tests on the microfluidic hybridization chip  20 . After the detection, the waste solution can be sent to the waste bottle  402  using the same control system.  
         [0031]    In comparison with the prior art, the invention provides a hybridization detection system with a faster reaction rate, automatic operations, and a lighter weight:  
         [0032]    1. The invention has a small platform design. The disclosed auto control system includes the test agent transmissions, positioning controls, hybridization monitoring, and detection signal controls. All of them can be controlled through a touch-control monitor. It is very convenient and simple.  
         [0033]    2. The invention is based upon the idea of a microfluidic chip and aims at providing rapid and correct results.  
         [0034]    3. The disclosed microfluidic chip hybridization platform can accommodate chips of different purposes.  
         [0035]    Certain variations would be apparent to those skilled in the art, which variations are considered within the spirit and scope of the claimed invention.