n/a
n/a
The present invention relates to a fully automatic genetic testing device. More specifically, the present invention relates to a compact, fully automatic genetic testing device with which a step of extracting and purifying nucleic acid contained in a sample, a step of injecting a solution containing the nucleic acid to a test chip, and a step of amplifying and detecting the nucleic acid can be fully automatically carried out, and with which genetic testing can be carried out near a patient.
At present, in the field of medicine, genetic testing is employed mainly for diagnosis of infections. By carrying out genetic testing, and taking the observed genetic testing results into account, physicians identify infections to give appropriate treatment.
Future practical application of genetic testing to cancer diagnosis and companion diagnosis has been expected. At present, thanks to rapid development of genetic analysis technologies, next-generation sequencers have been developed, and genome analysis has been accelerated. Genetic testing is now therefore hopeful test means for cancer diagnosis and companion diagnosis. However, genetic testing still requires a lot of time for obtaining the genetic testing results, and requires a high cost for obtaining the genetic testing results.
Examples of the genetic testing methods employed for genetic testing include real-time PCR and real-time LAMP (Loop-Mediated Isothermal Amplification), in which the nucleic acid amplification process is measured in real time. In particular, real-time LAMP has an advantage in its high gene amplification efficiency. At present, genetic testing devices to which genetic testing methods such as real-time PCR and real-time LAMP are applied have become commercially available. Normally, for such a genetic testing device, a pretreatment step for extraction and purification of nucleic acid from samples is carried out by an extraction/purification device provided separately from the test device, or by manual operation of the test device by a skilled operator.
In cases where genetic testing is carried out using a conventional genetic testing device, each of the step of extraction and purification of nucleic acid from samples, the step of injecting a solution containing the nucleic acid to a test chip, and the step of amplification and detection of nucleic acid, requires a complicated operation, so that the operator needs to be highly skilled. Moreover, since the genetic testing devices are expensive, the genetic testing devices have not yet been widely introduced in medical institutions.
Integrated devices which carry out nucleic acid extraction and diagnostic testing for a large number of biological samples have been proposed. Such integrated devices are systems for amplifying and detecting nucleic acid contained in extracted samples. The systems are microfluidic systems in which nucleotides are detected by carrying out PCR (polymerase chain reaction) for a large number of nucleotide samples of interest in microfluidic channels (microchannels).
However, integrated devices for nucleic acid extraction and diagnostic testing are configured such that they operate in association with a complementary rack, and the complementary rack is constituted such that it receives a large number of biological samples in a form suitable for detailed examination and diagnostic analysis, and a large number of holders having various reagents, pipette tips, and containers. The integrated device is a genetic testing device employing a self-contained system having a liquid dispenser for achievement of extraction from nucleic acid and a detection section that are integrated together. That is, since the liquid dispenser of the integrated system does not have a robust structure, nucleic acid contained in samples is influenced by disturbances in the environment in which the genetic testing is carried out.
Moreover, conventional genetic testing devices are large-sized, high-throughput screening type genetic testing devices which are in forms suitable only for genetic testing department of large hospitals, genetic testing companies, and the like. Therefore, since the above genetic testing devices cannot be placed in examination rooms for physicians, those genetic testing devices do not enable genetic testing at a position close to a patient.
In view of this, an object of the present invention is to provide a compact, fully automatic genetic testing device with which a step of extracting and purifying nucleic acid from a sample, a step of injecting a solution containing the nucleic acid to a test chip, and a step of amplifying and detecting the nucleic acid can be fully automatically carried out, and which enables a physician to carry out genetic testing at a position close to a patient while examining the patient. Another object of the present invention is to provide a fully automatic genetic testing device that is applicable to a variety of samples.
As a result of intensive study, the present inventors discovered that a compact, fully automatic genetic testing device which enables fully automatic genetic testing, and which enables a physician to carry out the genetic testing at a position close to a patient while examining the patient, can be provided by inclusion of a first unit for extracting and purifying nucleic acid from a sample; a second unit for injecting a solution containing the nucleic acid to a multi-well chip having a reaction site(s) for amplification of the nucleic acid; and a third unit for optically detecting nucleic acid amplified in the reaction site(s); thereby completing the present invention. More specifically, the present invention is constituted by the following technical matters.
(1) A fully automatic genetic testing device comprising: a first unit for extracting and purifying nucleic acid from a sample; a second unit for injecting a solution containing the nucleic acid to a multi-well chip having a reaction site(s) for amplification of the nucleic acid; and a third unit for optically detecting nucleic acid amplified in the reaction site(s).
(2) The fully automatic genetic testing device according to (1), wherein the first unit comprises: a pipetting mechanism for transferring a plurality of reagents to be used for the extraction and purification of the nucleic acid, between a cartridge containing the reagents and a reaction cell; and a treatment mechanism for pretreatment of the reaction cell; and wherein the treatment mechanism comprises at least one treatment section selected from the group consisting of a heating-cooling treatment section, stirring treatment section, and magnetic field application treatment section.
(3) The fully automatic genetic testing device according to (2), wherein the cartridge comprises: cells with a seal, for individually storing the plurality of reagents; a first cell for storing a piercing tip for opening a hole in the seal; a second cell for storing a pipette tip for transferring the reagents; and a third cell for storing an injection tip for injecting the solution containing nucleic acid into the reaction site(s).
(4) The fully automatic genetic testing device according to (3), wherein the injection tip is constituted by a syringe for retaining the solution containing nucleic acid, and an injection needle, the injection needle being connected to the syringe.
(5) The fully automatic genetic testing device according to (2), wherein the pipetting mechanism comprises: a first mechanism for opening a hole in the seal by bringing the piercing tip into contact with the seal; and a second mechanism for removing the piercing tip from the pipetting mechanism, attaching the pipette tip to the pipetting mechanism, and then transferring the reagents to the reaction cell.
(6) The fully automatic genetic testing device according to (2), wherein the pipetting mechanism comprises: a third mechanism to which the piercing tip is attached; and an injection mechanism comprising, in the third mechanism, the injection tip for injecting the solution containing nucleic acid from an injection hole of the microwell chip to the reaction site(s) through the injection needle.
(7) The fully automatic genetic testing device according to (6), comprising a fourth mechanism for vibrating the microwell chip.
(8) The fully automatic genetic testing device according to (6), comprising a control mechanism for detecting positional information of the tip portion of the injection needle from at least two directions and correcting the position of the tip portion of the injection needle to the position of the injection hole based on the positional information.
(9) The fully automatic genetic testing device according to (1), wherein the microwell chip has a plurality of channels connecting the injection hole to the reaction sites; and wherein amplification reaction of the nucleic acid is carried out in the reaction sites.
(10) The fully automatic genetic testing device according to (1), wherein the third unit detects nucleic acid amplified in the reaction sites based on turbidity and/or fluorescence.
(11) The fully automatic genetic testing device according to (5), wherein the cartridge comprises a cartridge base having a nearly circular plate shape, and wherein cells with a seal, the first cell, the second cell, and the third cell are arranged on the circumference of the circle which is the outer periphery of the cartridge base, the device comprising: a drive mechanism capable of moving the pipetting mechanism in the 0 direction; and a rotation mechanism capable of rotating the cartridge on the track along which the pipetting mechanism moves.
(12) The fully automatic genetic testing device according to (11), wherein the injection hole of the microwell chip is arranged at a position on the track along which the pipetting moves.
According to the present invention, a fully automatic genetic testing device with which a step of extracting and purifying nucleic acid from a sample, a step of injecting a solution containing the nucleic acid to a test chip, and a step of amplifying and detecting the nucleic acid can be fully automatically carried out, and which enables a physician to carry out genetic testing at a position close to a patient while examining the patient, is provided.
Further, according to the present invention, a fully automatic genetic testing device applicable to a variety of samples, wherein a pretreatment section having a robust structure is employed by avoiding integration of the pretreatment section and the optical test section of the genetic testing device with each other, is provided.
A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
Embodiments of the present invention are described below.
The master unit 2 controls the gene test system D. From the master unit 2, turning on/off of the power source, login and logout, sample data, and test items of genetic testing in the gene test system D are input, and measured test results and the like are displayed on a monitor. The user of the gene test system D begins genetic testing by, for example, touching the monitor of the master unit 2. According to commands instructed by the master unit 2, the genetic testing is carried out in the test unit 1.
In the test unit 1, when the lever is vertically positioned, the drawer provided in the lower side of the test unit 1 is unlocked. The user of the gene test system D can draw the inner portion of the test unit 1 by unlocking the drawer. The user of the gene test system D pulls up the lever of the test unit 1 from the lateral position to the vertical position. By pulling the vertically positioned lever in the direction toward the user of the genetic testing device D, the drawer portion of the test unit 1 can be removed, and samples can then be set therein for performing genetic testing. A technical feature of the gene test system D is the fully automatic genetic testing device 1 as a test unit. The fully automatic genetic testing device 1 of the present invention is described below.
In the fully automatic genetic testing device 1 of the present invention, the first unit corresponds to a pretreatment section 10 for extraction and purification of nucleic acid contained in the sample. The second unit corresponds to an injection section 20 for injection of a solution containing the nucleic acid extracted and purified by the first unit to a test chip. The third unit corresponds to an amplification detection section 30 for optically detecting nucleic acid amplified by the second unit. The fully automatic genetic testing device 1 can carry out fully automatic genetic testing by interactions of the first unit, second unit, and third unit with each other.
The first unit is a unit for extraction and purification of nucleic acid from the sample, and includes a cartridge 110 containing a plurality of reagents to be used for the extraction and purification of nucleic acid, a reaction cell 120, a pipetting mechanism 130 for transferring the reagents, and a pretreatment mechanism 140 for pretreatment of the reaction cell 120.
As shown in
The reagent cell with a seal 113a has a cylindrical shape. The reagent cell with a seal 113a has a flange 114a having a circular shape provided in the upper marginal part of the cell. The outer diameter of the flange 114a is larger than the outer diameter of each of the plurality of cartridge base holes 112 formed on the cartridge base 111. Thus, the reagent cell with a seal 113a is fixed to the cartridge base 111 by the flange 114a. The portion in which a reagent is retained in the reagent cell with a seal 113a is positioned in the back side of the cartridge base 111.
The cartridge 110 shown in
A seal 115 for storage of a reagent is attached to the opening section of the reagent cell with a seal 113. The inside of the reagent cell with a seal 113 is tightly closed since the opening section of the reagent cell with a seal 113 is covered by the seal 115. That is, the seal 115 functions as a lid for the reagent cell with a seal 113. The reagent retained in the reagent cell with a seal 113 by the seal 115 is not in contact with the ambient air. Thus, contamination, with impurities, of the reagent retained in the reagent cell with a seal 113 in each step of the genetic testing can be avoided, and reaction of the reagent with oxygen, water, carbon dioxide, and/or the like can also be avoided. The seal 115 shown in
The seal 115 tightly adheres to the surface of the cartridge base 111 and the flange 114. The material which can be employed for the seal 115 is required to be capable of tightly adhering to the materials constituting the cartridge base 111 and the flange 114. The material which can be employed as the seal 115 is also required to be capable of adapting to the temperature, pressure, and humidity at which the genetic testing is carried out, and to have an appropriate mechanical strength.
The seal 115 requires sufficient adhesiveness to the cartridge base 111. This is because, in cases where the adhesive strength between the seal 115 and the cartridge base 111 is insufficient, the whole seal 115 is drawn into the reagent cell with a seal 113 upon the later-mentioned contact of the tip portion of the piercing tip 117 to the seal 115.
Specific examples of the seal 115 include thin films composed of a synthetic rubber such as silicone rubber, nitrile rubber, acrylic rubber, or ethylene-propylene rubber, or of a plastic such as a polypropylene, polyethylene, polyethylene terephthalate (PET), polystyrene, or tetrafluoroethylene resin; and metal thin films such as aluminum thin films. The seal 115 may be constituted by a single-layer thin film, or may be a multi-layer thin film constituted by laminating a plurality of single layers composed of the same or different materials. For example, it may be a multi-layer thin film composed of an aluminum layer(s) and a polyethylene terephthalate (PET) layer(s).
The seal 115 has a thickness that allows formation of a hole by penetration of the tip portion of the piercing tip 117. The thickness of the seal 115 is not limited as long as the sealed state of the reagent cell with a seal 113 can be maintained, and as long as a hole can be made by the tip portion of the piercing tip 117.
The seal 115 may be transparent, semitransparent, or opaque. In cases where the seal 115 is transparent or semitransparent, the opening section of the reagent cell with a seal 113 can be externally recognized even after attachment of the seal 115 to the opening section of the reagent cell with a seal 113. The seal 115 attached to the opening section of the reagent cell with a seal 113 may be marked with a symbol, number, color, and/or the like. The cartridge 110 may also be provided with a two-dimensional bar code 35 for identification of the cartridge base plate 111. In such a case, the seal 115 may be opaque.
As shown in
Although
As shown in
Although
As shown in
The tip of the injection tip 118 is provided with an injection needle 1181 for injection of reagents. The injection needle 1181 is stored in the case 1191. The injection needle 1181 is therefore not in contact with the ambient air.
The reaction cell 120 shown in
The first unit has a pipetting mechanism 130 for transferring the reagent retained in the reagent cell with a seal 113 between the cartridge 110 and the reaction cell 120, and a pretreatment mechanism 140 for pretreatment of the reaction cell 120.
As shown in
The pipette head 131 is connected to the driving section 132. The driving section 132 can freely move on the XY-plane including the plane of the cartridge 110. The driving section 132 can freely move in the Z-axis direction including the vertical direction of the cartridge 110. The driving section 132 can also move on the XY-plane including the opening section of the reaction cell 120. The driving section 132 can move in the Z-axis direction including the vertical direction of the opening section of the reaction cell 120. That is, the driving section 132 can be three-dimensionally driven along the XYZ-axes.
The driving section 132 is controlled by a control section 133. The control section 133 is not limited as long as it is a member capable of moving the driving section 132 to a position at which the operation required for the genetic testing can be carried out. Examples of the control section 133 include XYZ robots and three-dimensional robots.
As shown in
The heating-cooling treatment section 141 has therein a heater 1411 necessary for heating or cooling of the reaction cell 120. The stirring treatment section 142 is supported by a supporting member 145. The magnetic field application treatment section 143 has therein a magnet 1431 and/or the like necessary for application of magnetic field to the reaction cell 120.
For the stirring treatment section 142, the rotation direction, rotation speed, rotation mode, and/or the like can be set as appropriate. The rotation by the stirring treatment section 142 can also be set to eccentric rotation. For example, by eccentric rotation of the stirring treatment section 142, a stirring effect can be obtained in a length of time about ten times shorter than that in cases of stirring by pipetting, which is conventionally carried out. Further, the eccentric rotation of the stirring treatment section 142 can contribute to shortening of the total process required for the genetic testing.
The pretreatment using the first unit is described below. The pretreatment using the first unit means extraction and purification of nucleic acid from a sample.
The pipette head 131 stops at a predetermined position in the cartridge 110 by movement of the driving section 132. The position of the pipette head 131 is set to a position above the tip hole 116 which stores the piercing tip 117 provided in the cartridge 110. The pipette head 131 stops at the corresponding fixed position, on the XY-plane, above the tip hole 116 which stores the piercing tip 117.
The pipette head 131 moves downward in the Z-axis direction. By the downward movement of the pipette head 131 in the Z-axis direction, the tip portion of the pipette head 131 fits into the piercing tip 117. By further applying, in the state where the tip portion of the pipette head 131 is fitted in the piercing tip 117, pressure downward in the Z-axis direction, the tip portion of the pipette head 131 connects to the piercing tip 117. Thus, the pipette head 131 can pick up the piercing tip 117. Here, the pipette head 131 to which the piercing tip 117 is connected is defined as a first mechanism 134.
The first mechanism 134 moves upward in the Z-axis direction. Subsequently, the position of the first mechanism 134 is set to a position above the reagent cell with a seal 113 in which a reagent is retained, provided in the cartridge 110. The first mechanism 134 stops at the corresponding fixed position, on the XY-plane, above the reagent cell with a seal 113.
The first mechanism 134 moves downward in the Z-axis direction. By the downward movement of the first mechanism 134 in the Z-axis direction, the tip portion of the piercing tip 117 of the first mechanism 134 is brought into contact with the seal 115 of the reagent cell with a seal 113. The first mechanism 134 further moves downward in the Z-axis direction. As a result, a predetermined pressure is applied to the seal 115, and the first mechanism 134 creates a hole having a predetermined hole size on the seal 115. The hole created on the seal 115 by the first mechanism 134 has a size sufficient for allowing insertion of the pipette tip 119. As described later, the hole created on the seal 115 is used for suction of the reagent by the pipette tip 119.
After the creation of the hole on the seal 115, the first mechanism 134 returns the piercing tip 117 attached to the pipette head 131 into the tip hole 116 in which the piercing tip 117 had been stored. In cases where a plurality of holes need to be created on the seal 115, the operation of moving the first mechanism 134 is repeatedly carried out. Subsequently, the tip portion of the pipette head 131 is made ready for attachment of the pipette tip 119.
The second mechanism 135 moves upward in the Z-axis direction. The second mechanism 135 stops at the corresponding fixed position, on the XY-plane, above the hole formed on the seal 115 of the reagent cell with a seal 113. The second mechanism 135 moves downward in the Z-axis direction. The second mechanism 135 moves downward in the Z-axis direction to pass through the hole, and the tip portion of the pipette tip 119 is brought into contact with the reagent retained in the reagent cell with a seal 113. Subsequently, the pipette tip 119 of the second mechanism 135 sucks the reagent retained in the reagent cell with a seal 113. The pipette tip 119 after the suction of the reagent moves to the reaction cell 120, and the sucked reagent is discharged into the reaction cell 120. In the reaction cell 120, the sample containing nucleic acid reacts with the reagent.
The pipette tip 119 of the second mechanism 135 can suck the solution resulting from the reaction of the solution containing nucleic acid with the reagent, and can then discharge the resulting solution into another reagent cell with a seal 113. The pipette tip 119 of the second mechanism 135 can repeat the process of sucking the reagent retained in the reagent cell with a seal 113, and the process of discharging the reagent into the reaction cell 120. The pipette tip 119 of the second mechanism 135 can also repeat the process of sucking the solution, retained in the reaction cell 120, resulting from the reaction of the sample containing nucleic acid with the reagent, and the process of discharging the resulting solution into another reagent cell with a seal 113. The control section 133 controls movement of the second mechanism 135.
As shown in
Into the reaction cell 120 that has been processed through Step 1, a magnetic bead solution and a buffer such as Binding Buffer retained in reagent cells with a seal 113 are added dropwise. The reaction cell 120 is then inserted into the heating-cooling treatment section 141 of the pretreatment mechanism 140, and heated. The heated reaction cell 120 is inserted into the stirring treatment section 142 of the pretreatment mechanism 140, and eccentric stirring is carried out to adsorb the extracted nucleic acid to the magnetic beads (Step 2). The first unit may also be capable of carrying out the operations of Step 1 and Step 2 as a single step instead of carrying out the Step 1 and the Step 2 as separate steps. That is, the first unit may have a structure with which Step 1 and Step 2 can be completed by a single step.
The reaction cell 120 that has been processed through Step 2 is inserted into a magnetism application treatment section 143 in the pretreatment mechanism, and magnetism is applied thereto to separate the magnetic beads present in the reaction cell 120. The cell lysis buffer such as Lysis Buffer present in the reaction cell 120 is removed by the pipette tip 119 (Step 3).
Into the reaction cell 120 that has been processed through Step 3, a washing liquid retained in a reagent cell with a seal 113 is added dropwise using the pipette tip 119. The reaction cell 120 containing the washing liquid is then inserted into the heating-cooling treatment section 141 of the pretreatment mechanism, and heated. The heated reaction cell 120 is inserted into the stirring treatment section 142 of the pretreatment mechanism 140, and eccentric stirring is carried out to wash the magnetic beads (Step 4).
The washing liquid present in the reaction cell 120 that has been processed through Step 4 is removed using the pipette tip 119. Into the reaction cell 120 after the removal of the washing liquid, a buffer such as Elution Buffer is added dropwise. The reaction cell 120 containing the buffer is then inserted into the heating-cooling treatment section 141 of the pretreatment mechanism 140, and heated. The heated reaction cell 120 is inserted into the stirring treatment section 142 of the pretreatment mechanism 140, and eccentric stirring is carried out to elute nucleic acid (Step 5).
The reaction cell 120 that has been processed through Step 5 is inserted into a magnetism application treatment section 143 of the pretreatment mechanism 140, and magnetism is applied thereto to separate the magnetic beads present in the reaction cell 120. By the separation of the magnetic beads, the eluted solution is provided as an extracted/purified solution (Step 6). Thus, according to the protocol shown in
The solution containing nucleic acid extracted and purified from the sample containing nucleic acid is sucked by the pipette tip 119. The solution containing nucleic acid is then discharged into the injection tip 118 stored in the cartridge 110. Thereafter, the pipette tip 119 is inserted through a tip hole 116 formed in the cartridge 110, and stored in a pipette tip case 1191.
The second unit is a unit for injecting a solution containing nucleic acid to a test chip such as a microwell chip having a reaction site for amplification of the nucleic acid obtained using the first unit. The second unit has an injection mechanism 210, and a microwell chip 220 having a reaction site for amplification of nucleic acid.
The tip portion of the pipette head 131 has a protruding portion, and is connected to a recessed portion of the piercing tip 117. The lower tip portion of the piercing tip 117 has a conical shape, and can fit into the opening section of the injection tip 118. To the lower tip portion of the injection tip 118, an injection needle 1181 is connected. The injection tip 118 has a syringe 1182, which is a portion retaining the solution containing nucleic acid extracted and purified by the first unit, and the injection needle 1181 connected to the syringe 1182.
The second unit also has a microwell chip 220 having a reaction site for amplification of the nucleic acid extracted and purified using the first unit. The microwell chip 220 is a test chip for genetic testing. The microwell chip 220 has a plurality of reaction sites 222 in the inside 221 thereof. The microwell chip 220 has, in the inside 221 thereof, microchannels 223 having a role in connecting a reaction site 222 to another reaction site 222. The microchannels 223 are constituted by a plurality of channels for connecting a plurality of reaction sites 222 to each other.
In the microwell chip 220, an injection hole 224 is formed. The injection hole 224 functions as a valve for insertion of the injection needle 1181. Through the injection needle 1181, the solution containing nucleic acid retained in the injection tip 118 is injected into the entire microwell chip 220 through the injection hole 224.
The injection hole 224 is not limited as long as it is a member capable of keeping reduced pressure conditions of the inside 221 of the microwell chip 220. Specific examples of materials that can be employed for forming the injection hole 224 include silicone resins, acryl silicone resins, polyvinyl chloride resins, and styrene-butadiene copolymer resins.
The microwell chip 220 is a closed system, and the pressure of the inside 221 thereof is set lower than the atmospheric pressure to provide reduced pressure. The closed system of the inside 221 of the microwell chip 220 can be maintained by the injection hole 224. The reaction sites 222 and the microchannels 223 constituting the microwell chip 220 are kept under reduced pressure conditions.
In the reaction sites 222 of the microwell chip 220, reagents necessary for nucleic acid amplification and nucleic acid detection are preliminarily dried and fixed. Examples of the reagents necessary for nucleic acid amplification and the reagents necessary for nucleic acid detection include, but are not limited to, reagents such as primers, probes, substrates, and enzymes. The necessary reagents are appropriately selected depending on the nucleic acid amplification reaction and the nucleic acid detection reaction carried out in the reaction sites 222.
The nucleic acid amplification reaction to be applied in the reaction sites 222 of the microwell chip 220 is not limited. The nucleic acid amplification reaction may be one using the following reactions. More specifically, an example of the nucleic acid amplification reaction is the PCR (Polymerase Chain Reaction) method, in which two kinds of primers are set for a target region, and a target gene is amplified 1,000,000- to 10,000,000-fold while the temperature is changed. Other examples of the nucleic acid amplification reaction include the LAMP (Loop-mediated isothermal Amplification) method and the SDA (Strand Displacement Amplification) method, which are isothermal amplification methods utilizing chain displacement activity of DNA polymerase. Still other examples of the nucleic acid amplification reaction include the TMA (Transcription Mediated Amplification) method, the NASBA (Nucleic Acid Sequence Based Amplification) method, and the TRC (Transcription-Reverse transcription Concerted) method, which are amplification methods utilizing T7 RNA polymerase to obtain RNA as the final amplification product.
Injection of the solution containing nucleic acid to the microwell chip 220 using the second unit is described below. The injection of the solution containing nucleic acid to the microwell chip 220 means injection of the solution containing nucleic acid retained in the injection tip 118 to the injection hole 224.
As shown in
The injection mechanism 210 retaining the solution containing nucleic acid stops at the corresponding fixed position, on the XY-plane, above the injection hole 224 of the microwell chip 220. By downward movement of the injection mechanism 210 in the Z-axis direction, the injection needle 1181 provided in the tip portion of the injection tip 118 pierces the injection hole 224. At this time, the injection tip 118 is connected to the reaction sites 222 and the microchannels 223 present in the inside 221 of the microwell chip 220, through the injection needle 1181.
As shown in
The injection mechanism 210 constituting the second unit of the fully automatic genetic testing device 1 of the present invention employs a simple structure in which an air path 1171 or 1172 is formed. Therefore, the injection mechanism 210 is capable of very simply and safely injecting the solution containing nucleic acid into the inside 221 of the microwell 220 by utilization of the differential pressure between the atmospheric pressure and the internal pressure of the microwell 220. Although the injection mechanism 210 is in a mode in which the air path 1171 or 1172 is formed to apply pressure to the solution containing nucleic acid, the mode capable of applying pressure to the solution containing nucleic acid is not limited thereto. For example, pressure may be applied to the solution containing nucleic acid by the pipette head 131 constituting the third mechanism 211.
In the injection mechanism 210 of the second unit, the pipette head 131 to which the piercing tip 117 is connected forms the tip portion of the third mechanism 211, and an injection tip 118 is provided at the tip portion. In the injection mechanism 210, the presence of the piercing tip 117 between the pipette head 131 and the injection tip 118 is effective for prevention of contamination of the pipette head 131 with the solution containing extracted and purified nucleic acid obtained by the first unit.
Thus, in the second unit, after the injection of the solution containing nucleic acid into the microwell chip 220, the injection mechanism 210 returns the injection tip 118 and the piercing tip 117 to their respective tip holes 116 formed in the cartridge 110.
The microwell chip 220 may have a fourth mechanism for vibrating the microwell chip 220 after the injection of the solution containing nucleic acid to the microwell chip 220 by the injection mechanism 210. The vibration by the fourth mechanism may be any of rotation, stopping, and horizontal vibration. The fourth mechanism causes the microwell chip 220 to vibrate. The vibration of the microwell chip 220 allows sufficient mixing of the reagents such as primers, probe, substrate, and/or enzyme fixed in the reaction sites 222 with the solution containing nucleic acid injected, resulting in improved reactivity in the nucleic acid amplification reaction. The vibration by the fourth mechanism is not limited as long as it can cause the microwell chip 220 to vibrate, and may be carried out by employing a motor or the like. The fourth mechanism is attached in the vicinity of the microwell chip 220, where the microwell chip 220 can be caused to vibrate.
The fully automatic genetic testing device 1 of the present invention may have a control mechanism 225 for detecting positional information of the tip portion of the injection needle 1181 from at least two directions and correcting the position of the tip portion of the injection needle 1181 to the position of the injection hole 224 based on the positional information.
The control mechanism 225 recognizes the deviation between the XY-plane coordinates, and controls the position of the injection needle 1181 such that the XY-plane coordinates at which the injection needle 1181 is actually positioned are accurately coincident with the XY-plane coordinates preliminarily stored in the control mechanism.
More specifically, photographs of the position of the injection needle 1181 are taken using the cameras from the two directions. By identifying the coordinates of the injection needle 1181 by image processing, and carrying out feedback control, the position of the needle tip of the injection needle 1181 can be controlled with an accuracy of ±0.1 mm or better.
For example, an injection needle 1181 having an outer diameter of about 0.5 mm may have a slight bend or an error in attachment to the container portion of the injection tip (for example, an injection-molded product of a polypropylene resin), causing a deviation of about ±0.3 mm in terms of the tip position of the injection needle. In cases where the injection hole 224 has a diameter of 1.0 mm, insertion of the needle tip of the injection needle 1181 into the injection hole 224 may be impossible in some cases due to positioning error of the test chip such as the microwell chip 220 and deviation of the position of the injection needle 1181.
Thus, in a case where the position of the needle tip of the injection needle 1181 can be controlled with an accuracy of ±0.1 mm or better, and where the positioning accuracy of the test chip such as the microwell chip 220 is about ±0.2 mm, the injection needle 1181 can be accurately and sufficiently inserted into the injection hole 224. The detection of the position of the injection needle 1181 is not limited to image processing using cameras, and may be optical detection of the positional information using infrared or the like.
The third unit is a unit for optically detecting the nucleic acid amplified in the reaction sites 222 of the microwell chip 220 of the second unit.
The excitation optical section 310 includes a base 311 as an outer frame, and an excitation light source, condensing lens 312, and collimating lens 313 arranged in a straight line in the order from the outside. The excitation light source, condensing lens 312, and collimating lens 313 arranged in a straight line form one excitation optical system. The third unit shown in
The third unit has the central section 320 for fixing the microwell chip 220. The central section 320 is constituted by the microwell chip 220, and two heaters 321 for holding the plate-shaped microwell chip 220 from both sides. For securing an optical path(s), an aperture(s) may be formed in each heater 321, or a transparent heater prepared by forming a thin film of a metal oxide such as indium tin oxide (ITO) on a glass substrate may be used. As shown in
The detection optical section 330 contains a base 331 as an outer frame, and a condensing lens 332, optical filter 333, and detector 334 arranged in a straight line in the order from the side of the microwell chip 220. The condensing lens 332, optical filter 333, and detector 334 arranged in a straight line form one detection optical system. The third unit shown in
Optical detection of nucleic acid by the third unit is described below. Light generated from the excitation light source in the excitation optical section 310 passes through the condensing lens 312, and then passes through the collimating lens 313. The light that has passed through the collimating lens 313 is filtered by the optical filter 314. The filtered excitation light passes through the holes formed in the upper heater 321, and then passes through the reaction sites 222 of the microwell chip 220. The excitation light that has passed through the reaction sites 222 of the microwell chip 220 passes through the condensing lenses 332, and is then filtered by the optical filter 333. The excitation light filtered by the optical filter 333 is detected by the detector 334.
As shown in
As described above, in the fully automatic genetic testing device 1 of Embodiment 1, a first unit for extracting and purifying nucleic acid from a sample, a second unit for injecting a solution containing the nucleic acid to a multi-well chip having reaction sites for amplification of the nucleic acid, and a third unit for optically detecting nucleic acid amplified in the reaction sites, interact with each other, and a robust structure is employed, so that genetic testing can be fully automatically carried out.
Since each of the first unit, second unit, and third unit of the fully automatic genetic testing device 1 has a compact structure, the whole genetic testing device can be made compact. Therefore, the fully automatic genetic testing device 1 enables genetic testing at a position close to a patient.
In
As shown in
The fully automatic genetic testing device 1 of Embodiment 2 has a driving section 432 which can move the pipetting mechanism 130 in the θ direction, and a rotation mechanism not shown which can rotate the cartridge 410 on the track along which the pipetting mechanism 130 moves. As shown in
Since the rotation mechanism can rotate the cartridge 410, the reagent cells 413 retaining the plurality of reagents required for the pretreatment, among the reagent cells with a seal 413, can be brought close to the pipetting mechanism 130. By rotating the cartridge 410 and then bringing the plurality of reagents required for the pretreatment close to the pipetting mechanism 130, picking up of the piercing tip 117 and suction of the reagents by the pipette tip 119 can be carried out rapidly and accurately. The θZ driving section 432 moves the pipetting mechanism 130 in the θ direction to carry out the operation of extraction and purification of nucleic acid from the sample on the cartridge base 411 and on the supporting member 444.
As shown in
The basic structure of the fully automatic genetic testing device 1 of Embodiment 3 is almost identical to that of the fully automatic genetic testing device 1 of Embodiment 1. The fully automatic genetic testing device 1 of Embodiment 3 employs the LAMP (Loop-Mediated Isothermal Amplification) method as the nucleic acid amplification reaction to be applied in the reaction sites 222 of the microwell chip 220.
By the employment of the LAMP method for the fully automatic genetic testing device 1, all reactions constituting the nucleic acid amplification reaction can be isothermally carried out; the amplification efficiency in the nucleic acid amplification reaction can be extremely increased; and very high specificity to a particular gene(s) can be achieved.
Further, in cases where the LAMP method is employed for the fully automatic genetic testing device 1, the time required for the nucleic acid amplification reaction can be about one hour. Further, in cases where the LAMP method is employed for the fully automatic genetic testing device 1 with application of a rapid method in which a loop primer and/or the like is added, the time required for the nucleic acid amplification reaction can be about 15 to 30 minutes. Further, in cases where the LAMP method is employed for the fully automatic genetic testing device 1, a large amount of magnesium pyrophosphate is produced as a by-product of the nucleic acid amplification reaction. Since magnesium pyrophosphate is a white precipitate that appears as a white suspension, occurrence of the nucleic acid amplification reaction can be visually detected even with the naked eye using as an index the white precipitate that appears as a white suspension. Thus, by simple measurement using the third unit, which is capable of optically detecting the level of white suspension (turbidity), genetic detection can be carried out.
The PCR method is the nucleic acid amplification reaction that is most widely used at present. However, it needs stepwise control of the reaction temperature for allowing the nucleic acid amplification reaction to proceed. In cases where the PCR method is used, gel electrophoresis needs to be used for checking by-products produced by the nucleic acid amplification reaction. Further, for checking by-products produced by the nucleic acid amplification reaction, a detection reaction using a probe needs to be separately carried out. In contrast, the fully automatic genetic testing device 1 of Embodiment 3 enables very simple control of the temperature as well as very simple operations since the device employs the LAMP method.
As important genetic testing devices in the field of medicine, genetic testing devices capable of obtaining the result of genetic testing in 30 minutes after obtaining samples have been demanded. Also for detection of environmental contaminant microorganisms in the environmental field, genetic testing devices capable of obtaining the result of genetic testing immediately after obtaining samples have been demanded. From such a point of view, the fully automatic genetic testing device of Embodiment 3, which employs the LAMP method, is of great technological significance since it has high operability, accuracy, functionality, and rapidity.
Although embodiments of the present invention are described above, the present invention is not limited to the above embodiments, and any modification of conditions or the like which does not depart from the spirit of the present invention is also included within the scope of application of the present invention.
As described above, the fully automatic genetic testing device of the present invention can fully automatically carry out the process from the step of extracting and purifying nucleic acid contained in a sample to the step of amplifying and detecting the nucleic acid. Therefore, its use as a compact, fully automatic genetic testing device which can be used near a patient can be expected. The fully automatic genetic testing device of the present invention can be used for various industries, especially for the medical device industry, pharmaceutical-related industries, agriculture-related industries, and the like.
It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.