KR101794736B1 - Method of extracting and amplifying nucleic acids using direct elution - Google Patents

Abstract

The present invention relates to nucleic acid extraction and amplification methods, and more particularly, to a nucleic acid extraction and amplification method by a direct elution reaction, and more particularly, to a nucleic acid extraction and amplification method using a direct elution reaction, How to do it.
Using the direct elution and amplification method of the nucleic acid using the elution and amplification reagent according to the present invention, the nucleic acid extraction whole process and the nucleic acid amplification can be performed by a one step method using one driving part. Accordingly, the present invention is easy to apply to nucleic acid extraction and amplification automation equipment.

Description

TECHNICAL FIELD The present invention relates to nucleic acid extraction and amplification methods using a direct elution reaction,

The present invention relates to nucleic acid extraction and amplification methods, and more particularly, to a nucleic acid extraction and amplification method by a direct elution reaction, and more particularly, to a nucleic acid extraction and amplification method using a direct elution reaction, How to do it.

Recently, much research has been conducted on techniques for extracting and amplifying nucleic acids from biological samples such as cells, bacteria, or viruses. Various methods have been developed for separating nucleic acids, proteins, etc. from biological samples. Sedimentation, liquid extraction, electrophoresis, and chromatography have been traditionally used, and a solid phase extraction method has been developed to simplify this operation. This solid phase extraction method is a method using solid particles having selectivity or using solid particles prepared by attaching a ligand having a high selectivity to a solid phase. In this method, a biological sample is first dissolved in a solution to which a target substance is selectively adhered. Then, the target material is adhered to the solid phase, the solid is separated from the solution, the residual liquid remaining on the solid phase is washed to remove other impurities, It is a principle to remove again with solution. The solid phase extraction method has been used either by filling the column with solid particles or by filling the filter membrane with a column. In this case, in order to increase the adhering capacity, a filter type membrane is used when fine particles having a large surface area or few samples are used. However, there is a problem that the solution flows very slowly between fine pores when filled with such fine particles or using a filter type membrane. So we use a centrifuge to increase the gravity value or pressurize or vacuum to give a pressure difference to flow the solution quickly. Also, methods and equipments for removing the solution have been developed by using fine magnetic particles having a large surface area, rapidly attaching biochemical substances in a suspended state of a solution, applying a magnetic field to agglomerate the magnetic particles with the target material attached thereto, and then removing the solution .

As an example of a conventional nucleic acid extraction technique, there is a method of treating a sample containing cells with SDS or proteinase K, followed by solubilization, and denaturing the protein with phenol to purify the nucleic acid. However, since the phenol extraction method requires a lot of processing steps, it takes a lot of time and the efficiency of the nucleic acid extraction depends greatly on the experience and the skill of the researcher. In recent years, a kit using silica or glass fiber that specifically binds to nucleic acid has been used to solve this problem. Since the silica or glass fiber has a low binding ratio with proteins and cellular metabolites, a relatively high concentration of nucleic acid can be obtained. Such a method is advantageous in comparison with the phenol method. However, since the chaotropic reagent or ethanol which strongly inhibits the enzyme reaction such as PCR is used, these substances must be completely removed. (Patent WO2013118990 A1)

Conventional techniques for extracting nucleic acid include a method in which each reagent necessary for nucleic acid extraction, such as a cell crushing reagent, a washing reagent, and an elution reagent, is contained in different containers, and the nucleic acid bound to the magnetic beads is transferred to the respective containers using a magnet. Alternatively, a reagent is injected into a single container using a pipette and a magnet, and reacted, followed by removing the reagent. The automation equipment for nucleic acid extraction using magnetic particles has been widely used because it is simply an automation of such conventional technology and it is easy to manufacture automation equipment. In this case, however, it is hard to see it as a true automation because there is an inconvenience in injecting a nucleic acid eluted sample into a nucleic acid amplification reagent separately. However, in addition to the nucleic acid extraction driving unit, a driving unit for transferring a certain amount of sample, called liquid handling, must be separately formed, and a sample In order to prevent evaporation after the injection, a driving part such as capping the amplification tube or sealing with oil is separately required, so the equipment implementation is very limited. As a background related to the present invention, there is a method of analyzing nucleic acid using magnetic particles disclosed in Korean Patent Laid-Open Publication No. 10-2013-0051647 (published on May 31, 2013).

In general, the bond between the silica support (bead) and the nucleic acid is caused by the univalent cation connecting the phosphoric acid portion of the nucleic acid and the silica support. If the concentration of the monovalent cation such as K ⁺ , Na ⁺ , CH ₆ N ₃ ⁺ , or NH ₄ ⁺ is insufficient, the nucleic acid immobilized on the silica is re-eluted. Therefore, Will use cations and the like at a high concentration of 500 mM to 1500 mM. In PCR buffer, monovalent cations are used to change the ionic condition of the PCR solution to neutral. If a direct elution is applied, the monovalent cations in the PCR buffer and the monovalent cations adsorbed in the beads are added to make the PCR inhibition environment. In some cases, the elution does not occur and the PCR reagent Primer / probe of the composition binds to the bead. Therefore, when the amplification is performed after the direct elution reaction, the amount of amplification differs from the amplification efficiency proceeding in general qPCR, and there arises a problem that the direct elution reaction is difficult.

It is an object of the present invention to provide an elution and amplification reagent capable of a direct elution reaction and capable of carrying out all the steps of nucleic acid extraction using nucleic acid and nucleic acid amplification using a one- Method. The present invention solves the problem that the conventional direct elution reaction is difficult, and provides an electrification method which can be a direct elution reaction and can be one step from nucleic acid extraction to amplification. That is, conventionally, the elution reaction is carried out in the eluting reagent after the washing, and then the container for the PCR reaction is transferred to integrate the steps which have to be performed in the new reagent, so that the one step electrophoresis is possible from extraction of the nucleic acid to amplification.

According to one aspect of the present invention, there is provided a nucleic acid extraction and amplification method comprising the steps of: (a) separating a nucleic acid by mixing a biosample, a lysis reagent, and a magnetic bead in a first container, Forming a bead complex; (b) transferring the nucleic acid-magnetic bead complex to a second container; (c) transferring the washed nucleic acid-magnetic bead complex to a third container, mixing the eluted and amplified reagent and eluting the nucleic acid; And (d) amplifying the eluted nucleic acid in the third container in an elution and amplification reagent containing 75 mM or less of monovalent cations. The magnetic beads preferably have a size of 200 nm to 5 탆, and are preferably contained in the grinding reagent at 1 to 4 g / L. It is preferable that a plurality of the second vessels are provided.

In another aspect of the present invention, a channel layer may be formed between the first container and the second container, and between the second container and the third container, with a hydrophobic substance. The hydrophobic material may include at least one selected from the group consisting of paraffin wax, polyethylene wax, and glue.

In another aspect of the present invention, the substances included in each of the first container, the second container, and the third container can be moved by one driving unit. At this time, the result of step (a) may be moved to the second container by the driving unit, and the result of step (b) may be moved to the third container by the driving unit. The driving unit may include a magnet for moving the magnetic beads.

In another aspect of the present invention, it is preferable that the magnetic beads are hydrophilic magnetic beads, and the third container is provided with an oil cover layer. The hydrophilic magnetic beads may have a hydrophilic coating layer on the surface of the magnetic beads. At this time, the hydrophilic coating layer is preferably formed of an organic material having at least one hydrophilic functional group among aldehyde, amine, alcohol, epoxy, and NHS (N-hydroxysuccinimide). When the washed nucleic acid-magnetic bead complex of step (b) moves to the third container, the bio-material other than the nucleic acid bound to the hydrophilic magnetic bead is further removed by the oil cover layer. The evaporation of the elution and amplification reagent can be suppressed by the oil cover layer. In this case, in the step (d), evaporation of the elution and amplification reagent may be less than 5 vol%. The volume of the oil cover layer is preferably 0.5 times or more the volume of the elution and amplification reagent.

Yet another aspect of the present invention provides a nucleic acid amplification method comprising amplifying a nucleic acid from a nucleic acid-magnetic bead complex and then incorporating a monovalent cation of 75 mM or less in the direct elution and amplification method.

Using the direct elution and amplification method of the nucleic acid using the elution and amplification reagent according to the present invention, the nucleic acid extraction whole process and the nucleic acid amplification can be performed by a one step method using one driving part. Accordingly, the present invention is easy to apply to nucleic acid extraction and amplification automation equipment.

Particularly, the nucleic acid extraction and amplification method according to the present invention can perform nucleic acid elution and amplification in a single container by performing nucleic acid elution in a PCR pre-mixture (elution and amplification reagent) in which an oil cover layer is formed Therefore, the fluid transfer module can be omitted and the device can be simplified. Further, by using the oil cover layer, it is possible to omit a separate tube capping process or a sealing process at the time of nucleic acid amplification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a conventional nucleic acid extraction and amplification method.
FIG. 2 is a schematic diagram showing a nucleic acid extraction and amplification method according to an embodiment of the present invention.
3 shows an example of a third container in which a nucleic acid elution process and a nucleic acid amplification process are performed.
4 shows an example of a driving part including a magnet and a protector.
5 shows an embodiment in which a hydrophobic channel layer is formed between each container and the container.
6 shows the PCR efficiency according to the amount of magnetic beads used.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a nucleic acid extraction and amplification method according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a conventional nucleic acid extraction and amplification method. FIG. 2 is a schematic diagram showing a nucleic acid extraction and amplification method according to an embodiment of the present invention. 1 and 2, the nucleic acid extraction and amplification method includes a lysis process for separating a nucleic acid through cell grinding and binding magnetic beads, a washing process for removing a substance other than the nucleic acid bound to the magnetic beads An elution process for separating the magnetic beads through nucleic acid dissolution, and a nucleic acid amplification process for amplifying the nucleic acid.

As in the example shown in FIG. 1, in the conventional case, after performing the elution process, a process of injecting a sample into a PCR container for nucleic acid amplification and performing a PCR container capping or sealing after injecting the sample is required . Accordingly, in the conventional case, a plurality of driving parts such as a magnet module for nucleic acid movement combined with a magnetic bead by a magnetic force, a fluid movement module for injecting a sample into a PCR container, a module for PCR container capping, .

However, as in the example shown in FIG. 2, in the case of the present invention, the elution and amplification steps in the PCR pre-mixture (elution and amplification reagent) in which the oil cover layer is formed are performed in the same vessel, And a driving unit such as a fluid movement module or robotics may not be required. In the case of the nucleic acid extraction and amplification method according to the present invention, it is possible to perform a one step nucleic acid extraction and amplification automation system by performing the pre-nucleic acid extraction and amplification by a single driving unit that provides a magnetic force.

Hereinafter, the direct elution and the nucleic acid extraction and amplification method using the amplification reaction according to the present invention will be described in detail with reference to the drawings and one embodiment.

2, the nucleic acid extraction and amplification method according to the present invention includes a bio-sample injection process, a lysis process, a washing process, an elution and an amplification process.

In the bio-sample injection process, a bio-sample is injected into a first container containing cell-disrupting reagents and magnetic beads.

Next, the lysis process is performed in a first vessel, in which the nucleic acid is separated from the biosample through cell grinding, and then a nucleic acid-magnetic bead complex is formed in which the nucleic acid and the hydrophilic magnetic beads are combined. The binding of the nucleic acid and the magnetic bead is preferably performed at room temperature or higher. For efficient coupling with nucleic acids, the magnetic beads preferably have a size of 200 nm to 5 mu m. If the magnetic beads are less than 200 nm, the movement may be difficult due to the magnetic property. If the magnetic beads are more than 5 μm, the surface area by weight may decrease and the binding conditions of the nucleic acids due to the electromagnetic force of the magnetic metal in the core of the beads may be changed. There is a possibility of decrease.

The nucleic acid-magnetic bead complex formed in the lysing process is transferred to the second container and then washed. In the washing step, washing is carried out in one or more second vessels in which the washing buffer is stored to remove the biomaterial other than the nucleic acid bound to the magnetic beads. At this time, in order to increase the purity of the nucleic acid, it is more preferable that a plurality of the second vessels are provided.

After the washed nucleic acid-magnetic bead complex is transferred to the third container, elution and amplification reactions are sequentially performed in the third container. In the present invention, elution and amplification of nucleic acid are performed in one container (third container).

In the third container, elution and amplification reagents may be stored. An elution process of separating the nucleic acid from the magnetic beads is performed by eluting the nucleic acid into the elution and amplification reagent. The separated nucleic acid is subjected to an amplification reaction in the same container without moving from the third container to the other container. Therefore, the elution reaction can be performed in the third container in which the elution and amplification reagents are stored, and then the amplification reaction can be sequentially performed. After the elution is carried out without changing the contents of the third container while maintaining the closed container state during elution, An amplification reaction can be performed.

To optimize both elution and amplification of nucleic acids, the present invention provides elution and amplification reagents capable of both elution and amplification reactions. Thus, the washed nucleic acid-magnetic bead complexes are eluted in the elution and amplification reagents, and then the eluted nucleic acids can be amplified in the same vessel and the same reagents (elution and amplification reagents). The elution and amplification reagent preferably contains a monovalent cation of 75 mM or less after the nucleic acid is eluted, and most preferably contains a monovalent cation of 50 mM or less. The direct elution reaction and the amplification reaction can be carried out even in the absence of the monovalent cation. However, if the monovalent cation exceeds 75 mM, the efficiency of the amplification reaction can be reduced.

According to the present invention, the nucleic acid-magnetic bead complex is washed in a washing solution, and then directly into a container containing a PCR buffer (elution and amplification reagent) without passing through a container containing an independent elution buffer, . At this time, a high concentration of monovalent cation included in the washing solution is introduced into the elution and amplification reagent together with the nucleic acid-magnetic bead complex so that the nucleic acid does not fall off from the bead. Such monovalent cations, for example, NH ₄ ⁺ , K ⁺ , Na ^+, etc. serve to protect the cation bridge connecting the surface of the magnetic beads with the nucleic acid in the washing solution, and the primer / probe primer / probe) and the target nucleic acid are stably coupled to perform the PCR. When the monovalent cation is present in an excessive amount in the PCR buffer, the double chain of the elongated target nucleic acid is prevented from being denatured Lt; RTI ID = 0.0 > PCR < / RTI > efficiency.

According to the present invention, for the direct elution and the amplification reaction, the concentration of the monovalent cation introduced from the bead and the concentration of the monovalent cation present in the PCR buffer are added to the solution to be 75 mM or less, more preferably 50 mM or less, Lt; RTI ID = 0.0 > and / or < / RTI > amplification reagents.

The present invention has been completed by discovering that when the concentration of the monovalent cation in the PCR buffer used is 75 mM or less, both elution and amplification of the nucleic acid can be sufficiently performed in the PCR buffer. Therefore, the present invention provides a nucleic acid-magnetic bead complex which can be subjected to direct nucleic acid elution and amplification reaction in the elution and amplification reagent without the step of re-adding the fluid sample to the PCR buffer after the elution reaction in the molecular experiment Direct elution and amplification methods are provided.

The concentration of monovalent cations in the PCR buffer may vary depending on the weight of the beads used for nucleic acid extraction. The amount of the magnetic beads to be used may vary depending on the kind and amount of the nucleic acid to be extracted and amplified, but it is preferably 1 to 4 g / L in the pulverization reagent. If the magnetic beads are less than 1 g / L, the amount of nucleic acid to be extracted is insufficient, and gene detection may become difficult. If the magnetic bead is more than 4 g / L, the amount of monovalent cations liberated from the magnetic beads increases during the elution reaction, and the amplification reaction of the nucleic acid may be inhibited and direct elution and amplification reaction may become difficult.

Generally, after the elution of the nucleic acid is completed, the eluted fluid sample is quantitatively injected into the nucleic acid amplification vessel. In the present invention, by eluting the nucleic acid in the third vessel in which the PCR amplification is finally performed, So that it can be performed in a unified manner. According to the present invention, the process can be simplified compared to the conventional method, and the device can be miniaturized and simplified because no separate fluid transfer module is required for amplification after elution, and a separate process for amplification after elution is not required. Amplification can be performed in one step.

In another aspect of the present invention, an oil cover layer may be formed on the third container. The nucleic acid-magnetic bead complex which is moved after the washing process is introduced into the third container through the oil cover layer, and the oil cover layer is separated from the third container during the elution and amplification reaction in the third container. The container can be sealed and evaporation of the reaction reagent can be prevented. Further, the filtering effect that the substance other than the target nucleic acid bound to the nucleic acid-magnetic bead complex is washed once by the oil layer may be exhibited.

The oil can be used without any particular limitation as long as it does not mix with the aqueous solution. The amount of oil used varies depending on the amplification reagent, and it is preferable that the volume of the oil cover layer is 0.5 times or more the volume of the elution and amplification reagent. If the volume of the oil cover layer is less than 0.5 times the volume of the elution and amplification reagent, the filtering effect may be deteriorated and the elution and amplification reagent or sample may be evaporated.

3 shows an example of a third container in which a nucleic acid elution process and a nucleic acid amplification process are performed. The third container 301 may be a container in which the elution and amplification reagent 310 is stored and amplification of the nucleic acid can be performed and a so-called polymerase chain reaction pre-mixture (elution and amplification reagent) . The oil cover layer 320 serves to filter substances other than the nucleic acid directly bonded to the hydrophilic magnetic beads and also serves to prevent evaporation of reagents and samples during amplification. With the oil cover layer 320, the evaporation of the amplification reagent in the amplification process may be less than 5 vol%. Further, since there is the oil cover layer, a separate PCR container capping process or the like can be omitted.

Further, since the sample passes through the oil cover layer in order to move into the third container, it is preferable to use a hydrophilic magnetic bead so that the magnetic bead is not mixed with the oil. When hydrophilic magnetic beads are used, they may be washed one more time by the oil cover layer formed in the third container when moving to the third container where the elution and amplification steps are performed after the washing process.

The hydrophilic magnetic beads may be in the form of a hydrophilic coating layer formed on the magnetic bead surface as a hydrophilic material. The hydrophilic material forming the hydrophilic coating layer may be an inorganic material such as alumina or silica or an organic material having at least one hydrophilic functional group selected from the group consisting of aldehyde, amine, alcohol, epoxy and NHS (N-hydroxysuccinimide). In bonding with the nucleic acid, the hydrophilic substance is more preferably an organic substance having the hydrophilic functional group. The organic substance having the hydrophilic functional group may be, for example, polyethylene glycol (PEG), polyvinyl alcohol (PVA) or the like.

Next, an amplification reaction of the nucleic acid is performed in the third container. In the elution step, the eluted nucleic acid is subjected to a conventional amplification reaction. A heat exchanger for amplification may be disposed in the third container. Further, in order to confirm the amplification in real time, a fluorescent substance may be provided to the elution and amplification reagent, and an optical unit for detecting the fluorescent substance in the vicinity of the third container may be additionally constituted.

Yet another aspect of the present invention is to move the materials contained in each of the first container, the second container, and the third container by one drive. The result of the lysing process can be moved to the second container by the driving unit and the result of the cleaning process can be moved to the third container by the driving unit. At this time, the driving unit may include a magnet for moving the magnetic beads. The movement of the magnet can be controlled in such a manner that it moves outside the container or in a manner that it is inserted and removed from the inside of the container. On the other hand, when the movement is controlled in such a manner that the magnet is inserted and removed from the container, the driving part may include a protector for preventing the magnetic bead from being directly coupled to the magnet, and the magnet may move within the protector.

4 shows an example of a driving part including a magnet and a protector. Referring to FIG. 4A, when stirring is performed, the magnet 410 is positioned outside the container 401 so that the magnetic bead 402 does not stick to the magnet 410. 4 (b), when the stirring result is moved to the next container after the stirring is completed, the magnet 410 is positioned in the container 401 so that the magnetic bead 402 adheres can do. At this time, the magnetic bead 402 is attracted to the protector 420 without being directly attached to the magnet 410 by the protector 420 that surrounds the magnet 410, 4 (a).

Another aspect of the present invention is to provide a process for the one step process wherein hydrophobic properties are maintained between the first and second containers and between the second and third containers so that the substances stored in each container do not mix with the substances stored in the other container The channel layer may be formed of a material. In addition, when the number of the second vessels is plural, a channel layer may be formed of a hydrophobic substance also between the second vessels. Preferably, the hydrophobic material includes at least one selected from the group consisting of paraffin wax, polyethylene wax and glue.

5 shows an embodiment in which a hydrophobic channel layer is formed between each container and the container. 5, a container for nucleic acid extraction, washing, elution, and amplification in which a hydrophobic channel layer is formed includes a body portion 510, a plurality of buffer storage portions 520, a plurality of channel portions 530, and a bottom portion 540, . ≪ / RTI > The buffer reservoir may contain buffers for extracting, washing, eluting and amplifying the nucleic acid from the biological sample, respectively. The buffers of the buffer storage unit 520 may be separated by the hydrophobic channel layer 530 filling the channel unit 530. The hydrophobic channel layer may be a non-polar phase change material that exists as a solid at room temperature and may have high separation stability because there is no fluidity at room temperature. The non-polar phase change materials may be selected from the group consisting of paraffin wax, polyethylene wax, and glue. In addition, the non-polar phase change material can be changed into a liquid phase by the heating unit 550. In this case, the phase change material has fluidity, and movement of the material through the channel portion 530 is enabled. Therefore, the magnetic particles having the nucleic acid attached thereto can be moved to the adjacent buffer storage part 520 through the channel part 530 using the magnetic force. At this time, since the hydrophilic nucleic acid is not mixed with the non-polar phase change material, it is possible to prevent the nucleic acid from being lost in the channel part 530 which may occur when the magnetic particles are moved. Then, if there is no heat supply from the heating unit 550, the non-polar phase change material in the liquid phase is again changed to a solid state. Therefore, it is possible to prevent the buffers from mixing again after the reaction.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Accordingly, the true scope of protection of the present invention should be defined by the following claims.

One) Magnetic bead  By usage PCR  efficiency

50 μl of a human blood sample was pulverized in 200 μl of a pulverization reagent (Gosen Biovid), and then mixed with 0.2 mg, 1 mg, 2 mg and 4 mg of magnetic beads of 300 nm coated with silica to prepare nucleic acid-magnetic bead complexes. The nucleic acid-magnetic bead complex was separated into a magnetic bar and washed with 300 μl of a washing solution (Gosen Biovid). The washed nucleic acid-magnetic bead conjugate was separated again into a magnetic bar and placed in 50 μl of a PCR buffer (Solvent), followed by stirring. After the nucleic acid bound to the magnetic particles was eluted from the PCR buffer, amplification was carried out directly without any additional treatment. Amplification was performed using a beta actin region present in human whole genomic DNA as a target. Primers and probes were designed using a self-designed sequence as described below.

Forward primer sequence (SEQ ID NO: 1): 5 'CATGTACGTTGCTATCCAGGC 3'

Reverse primer sequence (SEQ ID NO: 2): 5 'CTCCTTAATGTCACGCACGAT 3'

probe sequence (SEQ ID NO: 3): 5 'GTACCACTGGCATCGTGATG 3'

5 [mu] l of the amplification product was loaded into 3% agarose gel, and a marker of 100 bp was used. Positive control (PC) DNA was arbitrarily synthesized for use as a standard sample. In the experiment using 1 to 4 mg of magnetic beads, the amplification was not properly performed, and it was confirmed that a small amount of amplification was performed at 0.2 mg, which is 10 to 20 times smaller than that of the magnetic beads used in the conventional extraction method (FIG. 6) .

2) qPCR efficiency by bead usage in conventional PCR buffer

The amount of the beads was adjusted again to prepare a sample as in the above 1), and the qPCR experiment was performed. Since 1 mg of beads did not show the results, beads were used at intervals of 0.2 mg from 0.2 to 0.8 mg. Real-time PCR was performed to compare the results. As the amount of beads used increases, the surface area that the nucleic acid can bind becomes wider and the nucleic acid should be dissociated. However, the Ct value shows that the qPCR efficiency is gradually decreased. Therefore, it was confirmed that the direct elution and the amplification reaction can not be performed in the conventional extraction and PCR reagents.

Magnetic bead usage (mg) Ct value 0.2 25.27 0.4 25.28 0.6 25.54 0.8 28.17

3) PCR efficiency by KCl concentration

Experiments were conducted on the qPCR efficiency by the KCl concentration of the PCR buffer (Solzent Co.). PCR buffer was prepared by adding KCl to KCl free reagent at the required concentration as follows. As a sample used in the experiment, cDNA having a sequence of beta actin (1) prepared above was used at a concentration of 10 5 copies / μl.

The KCl concentration of the PCR buffer was adjusted to 0, 25, 50 and 75 mM, and 10 ^ 5 copies of the beta actin standard sample were injected into the PCR buffer.

The PCR buffer used as a standard in the market generally has a KCl concentration of 50 mM. As shown in Table 2 below, the qPCR efficiency shows the same efficiency up to KCl 50 mM, but the efficiency decreases sharply at 75 mM. This is because, in the direct elution and amplification reaction, when the amount of the bead is increased, the amount of the target nucleic acid is increased, so that the qPCR efficiency is not increased but the amount of the monovalent cation introduced from the bead is increased lt; RTI ID = 0.0 > qPCR < / RTI > efficiency.

KCl concentration (mM) Ct value 75 36.20 50 27.70 25 27.68 0 27.92

4) qPCR efficiency by magnetic bead usage in PCR buffer with KCl

In order to verify that the PCR efficiency is increased according to the amount of bead used when the KCl concentration is optimized, experiments were carried out with the KCl concentration of the PCR set at 0 mM and the bead quantities at 0.2, 0.4, 0.6, and 0.8 mg 3), and other experimental methods were the same as those in 2) above. As a result, it was observed that the qPCR efficiency was increased by bead usage different from the results of Table 1 which was performed in the conventional PCR buffer (KCl 50 mM).

Magnetic bead usage (mg) Ct value 0.2 25.78 0.4 25.18 0.6 24.94 0.8 23.07

Thus, it can be seen that qPCR efficiency can vary depending on bead usage, which depends on the final concentration of the cations in the PCR buffer. Conditions for optimizing the qPCR efficiency (target-specific amplification reaction) may vary depending on the target nucleic acid, but as shown in Table 2, when the target nucleic acid is dissociated, the monovalent cation concentration of the PCR buffer final solution is 75 mM Or less, more preferably a monovalent cation concentration of 50 mM or less.

301: Third container (body part)
310: elution and amplification reagent
320: Oil cover layer
401: container
402: magnetic bead
410: magnet
420: Protector
510:
520: Buffer storage unit
530:
540:
550:

<110> K-MAC <120> METHOD OF EXTRACTING AND AMPLIFYING NUCLEIC ACIDS USING DIRECT          ELUTION <130> k-mac-direct elution <160> 3 <170> KoPatentin 3.0 <210> 1 <211> 21 <212> DNA <213> Artificial Sequence <220> <223> Forward primer sequence <400> 1 catgtacgtt gctatccagg c 21 <210> 2 <211> 21 <212> DNA <213> Artificial Sequence <220> <223> Reverse primer sequence <400> 2 ctccttaatg tcacgcacga t 21 <210> 3 <211> 20 <212> DNA <213> Artificial Sequence <220> <223> probe sequence <400> 3 gtaccactgg catcgtgatg 20

Claims (16)

(a) separating a nucleic acid by mixing a biosample, a lysis reagent and a magnetic bead in a first container, wherein the magnetic bead is contained in the grinding reagent at 1 to 4 g / L to form a nucleic acid-magnetic bead complex;
(b) transferring the nucleic acid-magnetic bead complex to a second container;
(c) transferring the washed nucleic acid-magnetic bead complex to a third container, mixing the eluted and amplified reagent and eluting the nucleic acid; And
(d) amplifying the eluted nucleic acid in the third container with an elution and amplification reagent containing 50 mM or less of monovalent cations. The method according to claim 1,
Wherein a channel layer is formed between the first container and the second container and between the second container and the third container with a hydrophobic substance. 3. The method of claim 2,
Wherein the hydrophobic substance comprises at least one selected from the group consisting of paraffin wax, polyethylene wax, and glue. The method according to claim 1,
Wherein the substance contained in each of the first container, the second container, and the third container moves by one driving unit. 5. The method of claim 4,
Wherein the result of step (a) is transferred to the second container by the driving unit,
And the result of step (b) is transferred to the third container by the driving unit. 5. The method of claim 4,
Wherein the driving unit comprises a magnet for moving the magnetic beads. The method according to claim 1,
Wherein the magnetic beads have a size of 200 nm to 5 占 퐉. delete The method according to claim 1,
Wherein the magnetic beads are hydrophilic magnetic beads and the third container is provided with an oil cover layer. 10. The method of claim 9,
Wherein the hydrophilic magnetic bead has a hydrophilic coating layer formed on the surface of the magnetic bead. 11. The method of claim 10,
Wherein the hydrophilic coating layer is formed of an organic material having at least one hydrophilic functional group among aldehyde, amine, alcohol, epoxy, and N-hydroxysuccinimide (NHS). 10. The method of claim 9,
Wherein the volume of the oil cover layer is 0.5 times or more the volume of the elution and amplification reagent. 10. The method of claim 9,
When the result of step (b) is transferred to the third container, the bio-material other than the nucleic acid bound to the hydrophilic magnetic bead is further removed by the oil cover layer,
And the evaporation of the elution and amplification reagent is inhibited by the oil cover layer in the step (d). 14. The method of claim 13,
Wherein in the step of amplifying the nucleic acid in the third container, the evaporation of the elution and amplification reagent is less than 5 vol%. The method according to claim 1,
Wherein the second container comprises a plurality of second containers. In the direct elution and amplification method of nucleic acid, the nucleic acid is eluted from the nucleic acid-magnetic bead complex formed by combining the magnetic beads contained in the grinding reagent at 1 to 4 g / L and the nucleic acid of the biosample, Wherein the nucleic acid amplification composition comprises:

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