1. Technical Field
The present invention relates to a method for quantifying cellular biological material contained in a sample and a device for quantifying biological material.
2. Background Art
Examples of a conventionally known method (counting method) for quantifying microbes in a sample include what is called an ATP assay in which the number of microbes is indirectly counted by quantifying ATP (adenosine triphosphate) extracted from microbes. This ATP assay is a method including: causing an ATP extraction reagent to contact microbes contained in a sample; extracting endogenous ATP from the microbes; and counting the number of the microbes in accordance with an amount of luminescence when the ATP is reacted with a luminescent reagent.
The method of ATP assay is also used for hygiene management of water (e.g., see Patent Document 1), and is especially used for measuring microbes in soft drinks (e.g., see Patent Document 2). However, in a case where the number of microbes contained in a sample is counted, optical transparency, color and pH of the sample may affect accuracy of ATP quantification. In this regard, the quantification method in Patent Document 2 is configured to remove quantification inhibitors in the sample by adding a given processing reagent to the sample in advance.
Patent Document 1: Japanese Patent Application Publication No. 2005-138018
Patent Document 2: Japanese Patent Application Publication No. 2010-11759
However, in a case where the conventional ATP quantification method is applied for measuring ATP amount contained in microbes, the ATP amount contained in the microbes is a minute amount [amol (10−18 mol) level] to inhibit the ATP amount from being accurately quantified in a highly sensitive manner. In addition, since the processing reagent used for preprocessing of the sample also contains a minute amount of ATP, the conventional ATP quantification method fails to accurately quantify the ATP amount in a highly sensitive manner. Further, the conventional ATP quantification method finds it extremely difficult to control density of the processing reagent so as to deal with a quantification range of the ATP amount being at an amol level, inhibiting ATP amount from being accurately quantified in a highly sensitive manner.
Then, it is an object of the present invention to provide a method for quantifying biological material and a device for quantifying biological material that allow biological material of cells contained in a sample to be quantified more accurately in a highly sensitive manner than before.
In order to solve the above problems, the present invention provides a method for quantifying biological material of cells contained in a sample, including: a step of measuring a first amount of luminescence that measures an amount of luminescence when a luminescent reagent for biological material is reacted with the biological material that is separated and extracted from a cell by bringing a given processing reagent into contact with the sample; a step of measuring a second amount of luminescence that is performed with the step of measuring the first amount of luminescence in a pair and measures an amount of luminescence when the luminescent reagent for biological material is reacted with the given processing reagent and, and a step of quantifying the biological material that quantifies the biological material of cells contained in the sample based on a differential amount of luminescence between the amount of luminescence measured in the step of measuring the first amount of luminescence and the amount of luminescence measured in the step of measuring the second amount of luminescence.
Further, in order to solve the above problems, the present invention provides a device for quantifying biological material of cells contained in a sample, including a controller that calculates an amount of the biological material of cells contained in the sample based on a differential amount of luminescence between an amount of luminescence when a luminescent reagent for biological material is reacted with the the biological material that is separated and extracted from the cell by bringing a given processing reagent into contact with the sample and an amount of luminescence when the luminescent reagent for biological material is reacted with the given processing reagent.
The present invention can provide a method for quantifying biological material and a device for quantifying biological material that can quantify biological material of cells contained in a sample more accurately in a highly sensitive manner than before.
Next, a description will be given in detail of embodiments of the present invention by referring to the drawings as appropriate.
A method for quantifying biological material and a device for quantifying biological material of the present embodiment have a main feature in which the biological material contained in cells such as of microbes in a sample is quantified based on a differential amount of luminescence between an amount of luminescence of the biological material contained in cells such as of the microbes in the sample and an amount of luminescence of minute biological material contained in a processing reagent used for preprocessing the sample.
Hereinafter, the device for quantifying biological material will be described that quantifies ATP (adenosine triphosphate) as the biological material contained in the microbes in the sample. Then, the method for quantifying biological material of the present invention will be described, with description about operations of the device for quantifying biological material and a principal for quantifying the biological material.
As shown in
The separation/collection mechanism 4 separates/collects the ATP (biological material) from the microbes in the liquid sample 8a.
The separation/collection mechanism 4 includes a collection container 21 having a filter 26 therein, a filtration unit 2 that evacuates contents in the collection container 21 via the filter 26, and a liquid dispensing unit 31 that dispenses a given amount of a reagent and the like.
The collection container 21 separates the microbes contained in the liquid sample 8a that is injected therein, and extracts the ATP in the separated microbes for collection. The separation step of the microbes from the liquid sample 8a and the extraction step of the ATP from the microbes will be described later in detail.
The collection container 21 includes: a funnel-shaped main body 25; and the filter 26 arranged at a bottom of the main body 25. The filter 26 according to the present embodiment has two components in layers although not shown, a hydrophilic filter and a hydrophobic filter. The hydrophilic filter is disposed at the upper side and the hydrophobic filter is disposed at the lower side of the two components.
The filter 26 as so constructed can retain the liquid sample 8a injected into the main body 25 on the filter 26 unless the liquid sample 8a is sucked by a suction head 23 of the filtration unit 2 described later. In addition, when the liquid sample 8a is sucked by the suction head 23, the microbes (not shown) in the liquid sample 8a are retained on the filter 26 and liquid components can be discharged through the filter 26 to the suction head 23 side.
Meanwhile, the collection container 21 is detachably mounted on a predetermined position of a treatment stage 5 arranged in the device 1 for quantifying biological material.
The filtration unit 2 includes: the collection container 21 that also configures the above described separation/collection mechanism 4; the suction head 23; a lift mechanism 22 that moves the suction head 23 up and down; and a suction pump 24 that sucks the contents in the collection container 21 through the suction head 23.
As described above, the suction head 23 is movable up and down via the lift mechanism 22. When the contents in the collection container 21 are filtered by the filter 26, the lift mechanism 22 moves up the suction head 23 so that the suction head 23 is connected with the collection container 21. In addition, the collection container 21 is mounted on the treatment stage 5 or is removed from the treatment stage 5. In these cases, the lift mechanism 22 moves down the suction head 23 to disconnect the suction head 23 from the collection container 21.
Meanwhile, the suction pump 24 is arranged in the middle of a pipe P1 that extends from the suction head 23. When the suction pump 24 is actuated, the liquid components contained in the collection container 21, as described above, pass through the filter 26, the suction head 23, and the suction pump 24 to be discharged into a waste tank (not shown) of the device 1 for quantifying biological material.
In this connection, a suction pump controller 34d and a lift mechanism controller 34e of a control unit 34 can start and/or stop the suction pump 24 and the lift mechanism 22, respectively.
A liquid dispensing unit 31 includes: a liquid dispensing nozzle 31a; a dispensing pump 31b that sucks a predetermined amount of liquid from the liquid dispensing nozzle 31a or discharges that thereto; an actuator 31c that three-dimensionally moves the liquid dispensing nozzle 31a in a housing 7 of the device 1 for quantifying biological material; and an actuator controller 34a and a flow rate controller 34b of the control unit 34.
The liquid dispensing nozzle 31a of this liquid dispensing unit 31 is used in a step for measuring ATP luminescence intensity as described below. A predetermined amount of an ATP extract 8d (see
Note that the ATP luminescent reagent 8b corresponds to a “luminescent reagent for biological material” in claims.
In a case where an ATP amount contained in an ATP extraction reagent 8c, to be described later, as a processing reagent is measured, the liquid dispensing nozzle 31a dispenses the ATP extraction reagent 8c placed in the reagent holder 6 to the tube 32b for luminescence assay. In addition, the liquid dispensing nozzle 31a dispenses the ATP luminescent reagent 8b placed in the reagent holder 6 to the tube 32b for luminescence assay.
The actuator controller 34a controls the actuator 31c in a predetermined manner so that the liquid dispensing nozzle 31a moves three-dimensionally. In addition, the flow rate controller 34b controls the dispensing pump 31b in a predetermined manner so that dispensed amounts of the ATP luminescent reagent 8b, the ATP extraction reagent 8c and the ATP extract 8d (see
The ATP-quantification mechanism 3 primarily includes: the emission intensity-measuring unit 32; and an arithmetic part 34f of the control unit 34. The arithmetic part 34f determines quantity of ATP contained in microbes based on detection signals indicating ATP luminescence intensity, outputted from this emission intensity-measuring unit 32.
As described below in detail, the emission intensity-measuring unit 32 includes: the tube 32b for luminescence assay, the tube receiving the dispensed ATP extract 8d (see
Then, the main body 32a for light detection outputs the ATP luminescence intensity detection signals in the tube 32b for light detection to the arithmetic part 34f of the control unit 34. That is, the main body 32a for light detection outputs the detected signals of the “ATP luminescence intensity reflecting an amount of ATP in the ATP extract 8d” and the detected signals of the “ATP luminescence intensity reflecting an amount of ATP in the ATP extraction reagent 8c (processing reagent)”, respectively.
Note that the “ATP luminescence intensity reflecting an amount of ATP in the ATP extract 8d” corresponds to an “amount of luminescence when a luminescent reagent for biological material is reacted with biological material that is separated/extracted from a cell” in claims. In addition, the “ATP luminescence intensity reflecting an amount of ATP in the processing reagent” corresponds to an “amount of luminescence when the luminescent reagent for biological material is reacted with a given processing reagent” in claims.
The arithmetic part 34f calculates differential luminescence intensity between respective ATP luminescence intensities based on the detected signals of the “ATP luminescence intensity reflecting an amount of ATP in the ATP extract 8d” and the detected signals of the “ATP luminescence intensity reflecting an amount of ATP in the processing reagent”. Note that this differential luminescence intensity corresponds to a “differential amount of luminescence” in claims.
In addition, the arithmetic part 34f calculates ATP amount contained in the microbes in the liquid sample 8a based on this differential luminescence intensity. Note that a procedure of calculating the ATP amount in the arithmetic part 34f will be described later in detail.
Next, the method for quantifying biological material of the present invention will be described, with description about operations of the device 1 for quantifying biological material and a principle of quantifying biological material. Here, a description will be given with reference to
First, in the device 1 for quantifying biological material as shown in
The lift mechanism controller 34e of the control unit 34 commands the lift mechanism 22 so as to lift up the suction head 23 to couple with the collection container 21.
Then, the suction pump controller 34d of the control unit 34 activates the suction pump 24, allowing the suction head 23 to start filtering of the contents (liquid sample 8a) in the collection container 21 (step S1 in
Upon completion of the filtration of the contents in the collection container 21, a buffer solution is injected into the collection container 21 (step S2 in
Sterilized hot water or the like without ATP may preferably be used as the buffer solution.
Then, the suction pump controller 34d of the control unit 34 activates the suction pump 24, allowing the suction head 23 to restart the filtration of the contents in the collection container 21 (step S3 in
In the next step S4, an ATP eliminating reagent is dispensed into the collection container 21 (step S4 in
Incidentally, the ATP eliminating reagent is placed in the reagent holder 6 and is dispensed from the reagent holder 6 into the collection container 21 through the liquid dispensing nozzle 31a of the liquid dispensing unit 31.
The dispensation of this ATP eliminating reagent completely eliminates the ATP present outside the microbial cells. Examples of this ATP eliminating reagent include an ATPase.
In addition, the liquid dispensing nozzle 31a of the liquid dispensing unit 31 dispenses the ATP extraction reagent 8c into the collection container 21 under the control by the above-mentioned actuator controller 34a and the flow rate controller 34b (step S5 in
The dispensation of the ATP extraction reagent 8c allows the ATP contained in the microbes to be extracted, and the ATP extract 8d (see
Examples of the ATP extraction reagent 8c that can be suitably used include a surfactant, a mixed solution of ethanol and ammonia, methanol, ethanol, trichloroacetic acid, perchloric acid, and a Tris buffer. Among them, preferred is a surfactant. Examples of the surfactant include sodium dodecyl sulfate, potassium lauryl sulfate, sodium monolauroyl phosphate, sodium alkylbenzene sulfonate, benzalkonium chloride, benzethonium chloride, cetylpyridinium chloride, cetyl trimethyl ammonium bromide, and myristyl dimethyl benzyl ammonium chloride.
In addition, the liquid dispensing nozzle 31a of the liquid dispensing unit 31 dispenses the ATP extract 8d in the collection container 21 into the tube 32b for luminescence assay under the control of the actuator controller 34a and the flow rate controller 34b (step S6 in
Accordingly, in the tube 32b for luminescence assay, ATP in the ATP extract 8d reacts with the ATP luminescent reagent 8b to emit light.
In addition, the liquid dispensing nozzle 31a dispenses the ATP luminescent reagent 8b placed in the reagent holder 6 into the tube 32b for luminescence assay under the control of the actuator controller 34a and the flow rate controller 34b (step S7 in
Examples of the ATP luminescent reagent 8b include a luciferase-luciferin reagent.
Next, the arithmetic part 34f of the control unit 34 performs digital processing of detected signals outputted from the main body 32a for light detection after the main body 32a for light detection (see
Then, the control unit 34 temporarily stores a value (data) of the luminescence intensity measured by the arithmetic part 34f (the amount of luminescence measured in the step of measuring the first amount of luminescence) in a given storage section (not shown).
Next, the tube 32b for luminescence assay in the emission intensity-measuring unit 32 is replaced by a new one. The liquid dispensing nozzle 31a dispenses the ATP extraction reagent 8c (processing reagent) placed in the reagent holder 6 into the tube 32b for luminescence assay under the control of the actuator controller 34a and the flow rate controller 34b (step S9 in
In addition, the liquid dispensing nozzle 31a dispenses the ATP luminescent reagent 8b placed in the reagent holder 6 into the tube 32b for luminescence assay under the control of the actuator controller 34a and the flow rate controller 34b (step S10 in
This causes light emitted in this tube 32b for luminescence assay, through luminescent reaction between ATP in the ATP extraction reagent 8c (processing reagent) and the ATP luminescent reagent 8b.
Next, the arithmetic part 34f of the control unit 34 performs digital processing of detected signals outputted from the main body 32a for light detection after the main body 32a for light detection (see
Then, the control unit 34 temporarily stores a value (data) of the luminescence intensity measured by the arithmetic part 34f (the amount of luminescence measured in the step of measuring the second amount of luminescence) in the storage section.
Incidentally, the step of “measuring the first amount of luminescence” in step S8 and the step of “measuring the second amount of luminescence” in step S11 in the present embodiment are always performed in a pair.
Next, the arithmetic part 34f of the control unit 34 refers to the storage section (not shown) mentioned above to calculate the differential luminance intensity between the luminescence intensity measured in step S8 (the amount of luminescence measured in the step of measuring the first amount of luminescence) and the luminescence intensity measured in step S11 (the amount of luminescence measured in the step of measuring the second amount of luminescence) (step S12 in
Then, based on a standard curve defining a relationship between a pre-stored ATP amount (amol) and luminescence intensity (CPS), the control unit 34 calculates an ATP amount (amol) corresponding to the differential luminescence intensity measured above. That is, ATP in the liquid sample 8a (sample) is quantified based on the differential luminescence intensity (step S13 in
According to the device 1 for quantifying biological material and the method for quantifying biological material, following advantageous efforts can be obtained.
As shown in
In the next step S6, the ATP extract 8d in the collection container 21 is dispensed into the tube 32b for luminescence assay.
Once the ATP luminescent reagent 8b is dispensed into the tube 32b for luminescence assay (step S7 in
As shown in
Then, as described above, in step S12 shown in
In addition, as shown in
Therefore, the device 1 for quantifying biological material and the method for quantifying biological material have no difference to occur in the density of the processing reagent such as the ATP extraction reagent 8c and of the ATP luminescence reagent 8b, unlike the conventional quantification method. Thus, according to the device 1 for quantifying biological material and the method for quantifying biological material of the present invention, the microbe-derived ATP amount in the liquid sample 8a can be accurately quantified in a highly sensitive manner.
Hereinabove, the embodiment according to the present invention has been described. The present invention, however, is not limited to the above embodiment, and various modifications can be implemented.
In the embodiment described above, based on the standard curve defining the relationship between the pre-stored ATP amount (amol) and the luminescence intensity (CPS), the control unit 34 is configured to calculate the ATP amount (amol) reflecting the differential luminescence intensity in step S13 in
In
With the method for quantifying biological material in “the other embodiment (modification)”, as described in
The procedure of the method for quantifying biological material shown in
Then, as described above, in step S13 (see
On the other hand, in this modification, after the procedure shown in
This causes light emitted in the tube 32b for luminescence assay, through luminescent reaction of the ATP luminescent reagent 8b according to the ATP amount of the dispensed ATP standard reagent 8e. That is, with the ATP luminescence reagent 8b used in the procedure shown in
In this modification, as in step S12 (see
According to the modification like this, the ATP reflecting the differential luminescence intensity is quantified based on the “ATP luminescence intensity of the known ATP amount” actually measured by “using the same ATP luminescence reagent 8b as used for quantifying the ATP in the microbes”. Therefore, the microbe-derived ATP amount in the liquid sample 8a can be more accurately quantified in a highly sensitive manner.
In addition, the embodiment and “the other embodiment (modification)” are configured to measure the ATP luminescence intensity reflecting an amount of the ATP in the ATP extract 8d, and then, to measure the ATP luminescence intensity reflecting an amount of the ATP in the processing reagent. However, the present invention may be configured to measure the ATP luminescence intensity reflecting an amount of the ATP in the processing reagent, and then, to measure the ATP luminescence intensity reflecting an amount of the ATP in the ATP extract 8d.
Also, the device 1 for quantifying biological material may be configured to measure the ATP luminescence intensity reflecting an amount of the ATP in the ATP extract 8d in parallel with the ATP luminescence intensity reflecting an amount of the ATP in the processing reagent.
Further, although the ATP extraction reagent 8c is assumed as the processing reagent in the embodiment as described above, in the present invention, the ATP eliminating reagent can be included within a concept of the processing reagent. If the ATP eliminating reagent is included within the concept of the processing reagent, the purpose of using the processing reagent will be not for correcting the ATP amount of the ATP eliminating reagent but for correcting a density error thereof.
Still further, in the embodiment above, the ATP luminescence reagent 8b is dispensed into the tube 32b for luminescence assay for luminescence reaction after the ATP extract 8d or the ATP extraction reagent 8c (processing reagent) is dispensed. However, in the present invention, the ATP extract 8d or the ATP extraction reagent 8c (processing reagent) may be dispensed into the tube 32b for luminescence assay after the ATP luminescence reagent 8b is dispensed.
Yet further, in “the other embodiment (modification)”, the ATP standard reagent 8e may be dispensed into the tube 32b for luminescence assay after the ATP luminescence reagent 8b is dispensed.
Examples of the microbes of the above embodiments include, but are not limited to, gram-positive bacteria (e.g., Corynebacteria, Micrococcus, Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Bacillus subtilis), gram-negative bacteria (e.g., Citrobacter, Escherichia coli, Pseudomonas aeruginosa, Serratia), and fungi (e.g., Aspergillus oryzae, Penicillium notatum, Wallemia, Candida).
Note that when the present invention is applied to spore-forming bacteria such as Bacillus subtilis, the above reagent may further include a cell conversion reagent using nutrients such as amino acids and/or saccharides.
In addition, when an endotoxin contained in a cell membrane of gram-negative bacteria is quantified as a biological material. In this case, Limulus may be used as a luminescent reagent for biological material.
In addition, the above embodiments assume to quantify the biological material in the liquid sample 8a. However, for example, after the gel carrier is used to capture microbes floating in the air, this gel carrier placed in the collection container 21 may be mixed with a buffer solution or the like to prepare the liquid sample 8a.
In this connection, examples of the gel carrier include those made of material that causes a phase transition from gel to sol by raising the temperature from room temperature. Such a material is preferably liquefied in a range from 30° C. to less than 40° C. Examples of more preferable material among them include gelatin, a mixture of gelatin and glycerol, and a 10:1 copolymer of N-acryloyl glycinamide and N-methacryloyl-N′-biotinyl propylene diamine.
Number | Date | Country | Kind |
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2012-231771 | Oct 2012 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2013/078335 | 10/18/2013 | WO | 00 |