JP2007174935A - Method for extracting biological polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for extracting a biological polymer, by which a carrier for adsorbing an extract target such as DNA or RNA is used to extract the biological polymer in high extraction efficiency. <P>SOLUTION: The method for extracting the biological polymer, comprising operating so that a sample solution or the like reciprocatingly passes through the front and rear sides of the carrier in a microtube containing the carrier, whereby the adsorption of the biological polymer in the sample solution to the carrier is increased to efficiently improve the extraction of the biological polymer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for extracting biopolymers such as DNA and RNA, and in particular, the biopolymer in a sample can be efficiently removed by manipulating a sample solution or the like in a thin tube containing a carrier that adsorbs the biopolymer. It relates to a method of extraction.

The most commonly used method for extracting DNA and RNA from biological materials such as blood, body fluids, tissues and cells is a carrier comprising DNA or RNA made of SiO ₂ or the like in the presence of chaotropic salts (eg guanidine hydrochloride). After removing impurities (substances other than DNA and RNA to be extracted) by washing, the elution solution is added to elute the DNA and RNA from the carrier to obtain an elution solution containing DNA and RNA. The method is general (see Patent Document 1). In this extraction method, silica particles, glass, quartz wool, polymer, or the like can be used as the carrier. Regarding the extraction mechanism in this extraction method, it is presumed that after the biomaterial is dissolved in the presence of a chaotropic salt, the released DNA or RNA is adsorbed to a negatively charged carrier by cation exchange. Therefore, the adsorption efficiency of DNA or RNA on the carrier can be considered as the reaction efficiency between the carrier surface and DNA or RNA.

  FIG. 4 is a diagram showing a work procedure in the above extraction method. As shown in FIG. 4, the sample solution is injected into the extraction container 1 containing the carrier 3, and a centrifugal force is applied to the carrier 3 so that the sample solution flows from the extraction container 1 toward the receiver 2 by a centrifuge or the like. DNA and RNA are adsorbed. Although not shown, operations such as washing for removing impurities and elution of DNA and RNA adsorbed on the carrier 3 can be performed thereafter by the same operation. Thus, the target DNA or RNA is recovered in the receptor 2 together with the elution solution.

Japanese Patent No. 2680462

However,
In the extraction method using the above-mentioned carrier, the extraction yield is determined by the adsorption efficiency of DNA or RNA to the carrier, so that the variation in the yield is large and a sufficient yield cannot be obtained in many cases. In order to improve extraction efficiency, complicated operations such as adjusting the optimum carrier, sample solution, and reaction conditions for each extraction target have been required.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a biopolymer extraction method having high extraction efficiency using a carrier to which an extraction target such as DNA or RNA is adsorbed.

  As a result of diligent research in view of the above-mentioned problems, the present inventor conducted an operation so that the sample solution and the like reciprocate through the carrier in a microtube containing the carrier, thereby It has been conceived that the extraction efficiency of the biopolymer can be improved by increasing the amount of adsorption to the carrier. In addition, it was conceived that the washing efficiency and the elution efficiency can be improved by performing the same operation during washing for removing impurities and elution of the adsorbed biopolymer.

  That is, the present invention is an extraction method for extracting a biopolymer contained in a sample solution, wherein the sample solution is introduced into a capillary tube containing a carrier capable of adsorbing the biopolymer to be extracted. It is intended to provide a biopolymer extraction method characterized in that a liquid is fed back and forth (reciprocating liquid feed) so as to pass through a carrier at least once.

  In the biopolymer extraction method of the present invention, the reciprocating solution is an adsorption process for adsorbing the extraction target biopolymer to the carrier, a washing process for washing the adsorbed carrier, and a biopolymer adsorbed on the carrier. It can also be performed in each of the elution processes.

  As described above, according to the biopolymer extraction method of the present invention, a biopolymer can be efficiently extracted by a simple operation using a carrier to which an extraction target such as DNA or RNA is adsorbed.

  Hereinafter, the best mode for carrying out the biopolymer extraction method of the present invention will be described in detail with reference to the accompanying drawings. 1 to 3 are diagrams illustrating embodiments of the present invention. In these drawings, the same reference numerals denote the same components, and the basic configuration and operation are the same. To do.

  FIG. 1 is a diagram showing a configuration example of an apparatus for carrying out the biopolymer extraction method of the present invention. As shown in FIG. 1, in this embodiment, a MEMS (Micro Electrode) in which a fine tubular channel (hereinafter referred to as “capillary”) having a diameter of 1 mm to 0.1 mm is formed on a substrate such as glass or plastic. Mechanical systems) Biopolymer extraction from sample solution using a chip. In the capillary, a carrier for adsorbing an extraction target is held as an extraction unit, and at least one end of the capillary is provided with a pressure adjusting pump for feeding a sample solution. As the carrier, silica monolith, glass, polymer or the like can be used.

  In the apparatus shown in FIG. 1, first, a sample solution containing DNA or RNA to be extracted is introduced into a capillary. By operating the pump, the sample solution is sent to the extraction unit and moved back and forth so as to pass back and forth through the carrier as shown in FIG. Thereafter, the sample solution is discharged from the capillary. Subsequently, a cleaning solution for removing impurities other than the extraction target is introduced into the capillary and sent to the extraction unit, and moved back and forth so as to pass back and forth through the carrier as in FIG. Thereafter, the washing solution is discharged from the capillary. Subsequently, an eluate for eluting the extraction target adsorbed on the carrier is introduced into the capillary and sent to the extraction unit, and moved back and forth so as to pass back and forth as in FIG. Finally, the elution solution is discharged from the capillary, and the extraction target can be obtained in the obtained elution solution.

  When the above operation is performed using the apparatus shown in FIG. 1, the amount of adsorption to the extraction target carrier can be increased by reciprocating the sample solution to the carrier, and the cleaning solution is reciprocated with respect to the carrier. By feeding the solution, the cleaning efficiency can be increased, and the elution amount of the extraction target can be increased by reciprocating the elution solution to the carrier. Therefore, according to the biopolymer extraction method of this embodiment, the extraction efficiency and yield of DNA or RNA to be extracted can be increased.

  On the other hand, as shown in FIG. 3, an extraction unit for extracting an extraction target such as DNA or RNA from a sample solution and a detection unit for detecting and measuring the extraction target extracted thereby are integrated. It is also possible to configure a MEMS chip. A capillary having a carrier that adsorbs an extraction target similar to that shown in FIG. 1 is formed in the extraction part of the MEMS chip, and a capillary having a plurality of bead chips is formed in the detection part. The detection unit may be composed of other detection means.

  Kits for carrying out the conventional biopolymer detection method shown in FIG. 4 are generally sold. When this kit is used, the sample solution is allowed to pass through the carrier by centrifugation or the like. However, the sample solution may pass only once through the carrier, and the passage speed may not be optimized. Could not get rate. On the other hand, it is possible to take measures such as increasing the amount of the carrier. However, there is a problem that the manufacturing cost of the kit is increased, and further, when the MEMS is used, the liquid feeding pressure must be increased. It will occur.

  On the other hand, according to the biopolymer detection method of the present embodiment, the MEMS chip is obtained by reciprocating the solution several times to several tens of times with respect to the carrier in each process of adsorption, washing and elution. Even without increasing the amount of the carrier, it is possible to improve the yield of the extraction target by high-speed and simple operation.

  According to the biopolymer detection method of the present embodiment, nucleic acid is extracted from a blood sample using the MEMS chip shown in FIG. 3, and the yield is compared with a conventional method. As a result, there is an individual difference for each blood sample. However, a yield of 2 to 5 times and an increase in yield were confirmed. In addition, the number of reciprocating liquids does not need to be the same in each process of adsorption, washing, and elution, and the effect can be further improved by changing each. For example, the adsorption process: the washing process: the elution process = 10: 2: 5 is set, or the adsorption process: the washing process: the elution process = 10: 1: 5, and the reciprocating liquid feeding is performed in the washing process. It may be set to not.

  In the above description, the sample solution is blood and the extraction target is nucleic acid. However, the present invention is not limited to this, and the biopolymer detection method of the present embodiment can be applied to other biopolymers. In addition, as for the carrier, a carrier made of a material suitable for the extraction target may be appropriately selected. Moreover, even if the sample is not only liquid but also gas, the biopolymer detection method of this embodiment can be applied in the same manner as described above.

  As mentioned above, although the specific embodiment was shown and demonstrated about the biopolymer extraction method of this invention, this invention is not limited to these. A person skilled in the art can make various changes and improvements to the configurations and functions of the invention according to the above-described embodiments or other embodiments without departing from the gist of the present invention. From now on, it is assumed that MEMS devices will mainly be used for diagnostic / test applications, and the biopolymer extraction method of the present invention is expected to be widely used because it can be implemented with simpler and higher performance devices.

It is a figure which shows the structural example of the apparatus for enforcing the biopolymer extraction method of this invention. It is a figure which shows a mode that a sample solution is reciprocated with respect to a support | carrier using the apparatus shown in FIG. It is a figure which illustrates the structure of the MEMS chip which integrated the extraction part for extracting extraction object, and the detection and measurement part for detecting and measuring the extracted extraction object. It is a figure which shows the operation | movement procedure in the conventional biopolymer extraction method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Extraction container 2 ... Receptor 3 ... Carrier

Claims (1)

An extraction method for extracting a biopolymer contained in a sample solution,
A sample solution is introduced into a capillary tube containing a carrier capable of adsorbing a biopolymer to be extracted,
A biopolymer extraction method comprising feeding a sample solution back and forth so that the sample solution passes through the carrier one or more times.

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