Filter suction holder, nucleic acid extraction system, and nucleic acid extraction method

Abstract

To make it easier to insert a filter into a reaction tube.SOLUTION: A filter suction holder 310 insertable into a reaction tube used for extracting nucleic acid from a specimen, together with a filter configured to capture the specimen by filtering a sample containing the specimen having nucleic acid, the filter suction holder including a container 311 for accommodating the filter, the container having an inner wall surface 312 configured to stick to a surface of the filter and cause the filter to be adsorbed.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a filter suction holder, a nucleic acid extraction system, and a nucleic acid extraction method.

Background Art

[0002] Patent Document 1 and Patent Document 2 disclose nucleic acid extraction methods.

[0003] In a conventional nucleic acid extraction method, a sample is filtered using a membrane filter, so that microorganisms in the sample are collected on the surface of the membrane filter. Then, the membrane filter is picked up with sterilized tweezers and inserted into a reaction tube, so that the membrane filter is accommodated in the reaction tube. Thereafter, a surfactant is added to the reaction tube, and the reaction tube is heated to a temperature above the boiling point to create a high-temperature and high-pressure state, and nucleic acids are extracted from the microorganisms.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The operation of collecting the filtered filter and inserting it into the reaction tube is very complicated because the very thin filter has to be handled with tweezers. Moreover, in order to extract nucleic acids, it is necessary to immerse the filter in a reaction solution containing a surfactant, but since the wet filter easily adheres to the inner wall of the reaction tube, it is difficult to insert the filter to the bottom of the reaction tube.

[0006] An object of the present disclosure is to facilitate the insertion of a filter into a reaction tube.

Means for Solving the Problems

[0007] Filter suction holders, nucleic acid extraction systems, and nucleic acid extraction methods according to some embodiments will be described below.

[0008] [1] A filter suction holder insertable into a reaction tube used for extracting nucleic acid from a sample containing a specimen having nucleic acid, together with a filter for collecting the specimen by filtering the sample, A filter suction holder including a housing portion for housing the filter, the housing portion having an inner wall surface that adheres to the surface of the filter and adsorbs the filter.

[0009] By using such a filter suction holder, it becomes easier to insert the filter into the reaction tube.

[0010] [2] The housing portion has a hollow conical or frustoconical shape, the bottom surface of the cone or the frustoconical shape is open to expose the inner wall surface, and the smaller diameter end of the cone or the frustoconical shape is inserted into the reaction tube, the filter suction holder according to [1].

[0011] By using such a filter suction holder, it becomes easier to insert the filter to the bottom of the reaction tube.

[0012] [3] The housing portion has heat resistance up to at least 180°C, the filter suction holder according to [1] or [2].

[0013] In such a filter suction holder, unintentional deterioration during heating can be prevented.

[0014] [4] The filter suction holder according to any one of [1] to [3], wherein the accommodating portion is formed of a material that melts when a certain amount of heat is applied.

[0015] By using such a filter suction holder, during nucleic acid extraction, the filter suction holder melts, increasing the area of contact between the filter and the reaction solution containing the surfactant, and improving the reaction efficiency.

[0016] [5] The filter suction holder according to any one of [1] to [4], further comprising a surfactant fixed to the accommodating portion.

[0017] By using such a filter suction holder, the operation of adding the surfactant required for nucleic acid extraction to the reaction tube can be simplified.

[0018] [6] A filter suction holder according to any one of [1] to [5], and A reaction tube capable of accommodating the filter suction holder together with the filter A nucleic acid extraction system comprising.

[0019] In such a nucleic acid extraction system, it becomes easier to insert the filter into the reaction tube.

[0020] [7] Collecting the sample containing the specimen having nucleic acid by filtering the sample using a filter, Accommodating the filter in an accommodating portion of a filter suction holder having an inner wall surface that closely adheres to the surface of the filter and adsorbs the filter, Inserting the filter suction holder together with the filter into a reaction tube, Extracting the nucleic acid from the specimen using the reaction tube A nucleic acid extraction method comprising.

[0021] In such a nucleic acid extraction method, it becomes easier to insert the filter into the reaction tube.

Advantages of the Invention

[0022] According to the present disclosure, it becomes easier to insert the filter into the reaction tube.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0024] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0025] In each figure, the same or corresponding parts are denoted by the same reference numerals. In the description of each embodiment, the description of the same or corresponding parts will be omitted or simplified as appropriate.

[0026] With reference to FIG. 1, the configuration of the nucleic acid analysis system 100 according to the present embodiment will be described.

[0027] The nucleic acid analysis system 100 includes a sample collection system 200, a nucleic acid extraction system 300, a hybridization reaction system 400, and a detection system 500.

[0028] The sample collection system 200 is a system that collects the sample contained in the sample 110 from the sample 110.

[0029] The sample is, for example, bacteria, fungi, viruses, or other microorganisms. When an inspection is performed on a beverage, the sample 110 is the manufactured beverage. Alternatively, the sample 110 may be the water for manufacturing the beverage. Alternatively, the sample 110 may be the liquid generated during the manufacturing process of the beverage. When inspecting the presence or absence or degree of contamination of bacteria in the manufacturing environment, if bacteria are recovered from the cotton swab into the liquid by vibrating the cotton swab taken from the inspection environment in the liquid or vibrating the liquid containing the cotton swab, the sample 110 may be the liquid.

[0030] The specimen collection system 200 includes a filter 210 as shown in FIG. 2.

[0031] The collection is performed, for example, by pressurizing or depressurizing the sample 110 and filtering it through the filter 210. When bacteria or fungi are collected, the pore size of the filter 210 is, for example, 0.45 mm or 0.22 mm.

[0032] Specifically, the filter 210 is a membrane filter. The diameter of the filter 210 is, for example, 13 mm. The filter 210 may have a size that can be inserted into the reaction tube 320 described later. The shape of the filter 210 is, for example, circular. The material of the filter 210 is, for example, MCE, PVDF, PES, or PC. "MCE" is an abbreviation for mixed cellulose ester. "PVDF" is an abbreviation for polyvinylidene fluoride. "PES" is an abbreviation for polyethersulfone. "PC" is an abbreviation for polycarbonate.

[0033] The nucleic acid extraction system 300 is a system that extracts the nucleic acid contained in the specimen recovered by the specimen collection system 200.

[0034] The nucleic acid extraction system 300 includes a filter suction holder 310 as shown in FIG. 3 and a reaction tube 320 as shown in FIG. 4.

[0035] After the sample is collected by the filter 210, the filter 210 is transferred to the filter suction holder 310 using the tweezers 220 as shown in FIG. 2. The filter suction holder 310 adsorbs the filter 210. The filter suction holder 310 is inserted into the reaction tube 320 together with the filter 210. In this embodiment, instead of directly inserting the filter 210 into the reaction tube 320 using the tweezers 220, the filter 210 is first accommodated in the filter suction holder 310 and then inserted into the reaction tube 320. Therefore, the filter suction holder 310 can prevent the filter 210 from falling. By using the filter suction holder 310, the filter 210 can be fixed, making it easier to insert the filter 210 into the reaction tube 320. By using the filter suction holder 310, the filter 210 will not adhere to the inner wall of the reaction tube 320, making it easier to insert the filter 210 at the bottom of the reaction tube 320. Since the filter suction holder 310 is disposable, the risk of contamination can also be reduced.

[0036] Instead of the tweezers 220, vacuum tweezers may be used. By using the vacuum tweezers, the operation of pinching the filter 210 with the tweezers 220 becomes unnecessary, and the filter 210 can be recovered with a simple operation. Therefore, the filter 210 can be reliably recovered regardless of the skills of the operator.

[0037] After the filter 210 captures the sample by filtering the sample 110, the filter suction holder 310 is inserted into the reaction tube 320 together with the filter 210. Therefore, the filter suction holder 310 is sized to be insertable into the reaction tube 320.

[0038] The filter suction holder 310 includes a housing portion 311 for accommodating the filter 210. The housing portion 311 has an inner wall surface 312 that adheres to the surface of the filter 210 to adsorb the filter 210.

[0039] In the present embodiment, the housing portion 311 has a shape of a hollow cone or a frustum of a cone. The housing portion 311 has an opening at the bottom surface of the cone or the frustum of the cone to expose the inner wall surface 312. The housing portion 311 has a first end 313 corresponding to the bottom surface of the cone or the frustum of the cone, and a second end 314 corresponding to the apex of the cone or the opposite bottom surface of the frustum of the cone. The housing portion 311 is inserted into the reaction tube 320 from the second end 314 where the diameter of the cone or the frustum of the cone is smaller among the first end 313 and the second end 314.

[0040] In the present embodiment, not only the bottom surface of the housing portion 311 in the shape of a cone or a frustum of a cone but also the apex of the cone or the opposite bottom surface of the frustum of the cone are open. That is, openings are formed at both the first end 313 and the second end 314 of the housing portion 311.

[0041] It is desirable that the housing portion 311 has heat resistance up to at least 180°C. For example, the housing portion 311 may be formed of PES.

[0042] The housing portion 311 may be formed of a material that dissolves when a certain amount of heat is applied. For example, the housing portion 311 may be formed of a thermally decomposable polymer. When the housing portion 311 dissolves, the area of contact between the filter 210 and the reaction solution containing the surfactant during nucleic acid extraction increases, and an improvement in reaction efficiency can be expected.

[0043] The filter suction holder 310 may further include a surfactant fixed to the housing portion 311. For example, by previously drying the reaction solution containing the surfactant used for nucleic acid extraction and fixing it to the housing portion 311, the operation of adding the reaction solution can be simplified.

[0044] The reaction tube 320 has a structure capable of accommodating the filter suction holder 310 together with the filter 210. As the reaction tube 320, a general PCR tube can be used. "PCR" is an abbreviation for polymerase chain reaction. The capacity of the reaction tube 320 is, for example, 0.2 mL. Regarding the method of extracting nucleic acid from a sample using the reaction tube 320, since it is the same as known methods such as those disclosed in Patent Document 1 or Patent Document 2 except for using the filter suction holder 310, the description thereof is omitted.

[0045] A liquid containing another nucleic acid B that reacts with the extracted nucleic acid may be mixed with the sample 110 from which the nucleic acid has been extracted. Nucleic acid B may be a nucleic acid to which a site having a fluorescence, luminescence, or quenching action under specific conditions is imparted for detection by the detection system 500.

[0046] The hybridization reaction system 400 is a system for performing a hybridization reaction on the sample 110.

[0047] In the hybridization reaction system 400, the sample 110 is heated to, for example, 60° C. and stirred, thereby reacting with the nucleic acid that matches the aforementioned nucleic acid B. For example, a site having a fluorescence, luminescence, or quenching action under specific conditions imparted to nucleic acid B reacts with the nucleic acid in the sample 110, thereby expressing a fluorescence, luminescence, or quenching action. By using a nucleic acid whose structure is designed to react with a specific nucleic acid as nucleic acid B, nucleic acid B reacts only with, for example, the nucleic acid structure possessed by a specific microorganism. Therefore, in the treatment with this hybridization reaction system 400, by using a specific nucleic acid B, it is possible to cause the fluorescence, luminescence, or quenching action imparted to nucleic acid B to be expressed only when a specific microorganism is contained in the sample 110.

[0048] The detection system 500 is a system for detecting the presence, absence, and degree of the fluorescence, luminescence, or quenching action expressed by the reaction of nucleic acid B in the sample 110 processed by the hybridization reaction system 400.

[0049] For example, the detection may be performed by a method in which fluorescence generated by the reaction with the nucleic acid of sample 110, which is imparted to nucleic acid B, is excited by excitation laser light, and the fluorescence after excitation is detected by a high-sensitivity camera. Alternatively, the detection may be performed by a method in which chemiluminescence generated by the reaction with the nucleic acid of sample 110, which is imparted to nucleic acid B, is detected by a high-sensitivity camera. Alternatively, the detection may be performed by a method in which, with respect to the quenching action generated by the reaction with the nucleic acid of sample 110, which is imparted to nucleic acid B, the degree to which the fluorescence or luminescence imparted in the vicinity of the site where the quenching action is imparted is quenched is detected by a high-sensitivity camera.

[0050] By using such a nucleic acid analysis system 100, it becomes possible to analyze whether a specific microorganism is contained in sample 110 or its concentration.

[0051] With reference to FIG. 5, the nucleic acid extraction method according to this embodiment will be described.

[0052] The nucleic acid extraction method according to this embodiment includes a collection step S1, a housing step S2, an insertion step S3, and an extraction step S4. The collection step S1 is a step of collecting a specimen by filtering sample 110 containing the specimen having nucleic acid using filter 210. The housing step S2 is a step of housing filter 210 in housing portion 311 of filter suction holder 310 having inner wall surface 312 that adheres to the surface of filter 210 and adsorbs filter 210. The insertion step S3 is a step of inserting filter suction holder 310 together with filter 210 into reaction tube 320. The extraction step S4 is a step of extracting nucleic acid from the specimen using reaction tube 320.

[0053] By using such a nucleic acid extraction method, it becomes easier to insert filter 210 into reaction tube 320.

[0054] The present disclosure is not limited to the above-described embodiments. Modifications can be made without departing from the spirit of the present disclosure.

Description of Reference Numerals

[0055] 100 Nucleic acid analysis system 110 Sample 200 Specimen collection system 210 Filter 220 Tweezers 300 Nucleic acid extraction system 310 Filter suction holder 311 Accommodation part 312 Inner wall surface 313 First end 314 Second end 320 Reaction tube 400 Hybridization reaction system 500 Detection system

Claims

1. A filter suction holder that is insertable into a reaction tube used for extracting nucleic acid from a sample containing a specimen having the nucleic acid, together with a filter for collecting the specimen by filtering the sample containing the specimen having the nucleic acid, The filter suction holder includes a housing portion for housing the filter, the housing portion having an inner wall surface that is in close contact with the surface of the filter and adsorbs the filter.

2. The filter suction holder according to claim 1, wherein the housing portion has a hollow conical or frustoconical shape, the bottom surface of the cone or frustum is open to expose the inner wall surface, and the filter suction holder is inserted into the reaction tube from the end with the smaller diameter of the cone or frustum.

3. The filter suction holder according to claim 1, wherein the housing portion has heat resistance up to at least 180°C.

4. The filter suction holder according to claim 1, wherein the housing portion is formed of a material that dissolves when a certain amount of heat is applied.

5. The filter suction holder according to claim 1, further comprising a surfactant fixed to the housing portion.

6. A nucleic acid extraction system comprising the filter suction holder according to any one of claims 1 to 5, and a reaction tube capable of housing the filter suction holder together with the filter.

7. Collecting the specimen by filtering a sample containing a specimen having the nucleic acid using a filter; housing the filter in a housing portion of a filter suction holder having an inner wall surface that is in close contact with the surface of the filter and adsorbs the filter; inserting the filter suction holder together with the filter into a reaction tube; and extracting the nucleic acid from the specimen using the reaction tube. A nucleic acid extraction method comprising the above steps.

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