JP2007085930A - Method of using metal probe and analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide means capable of easily and reliably cleaning a metal probe.
First, the surface of a metal probe is subjected to a hydrophobic surface treatment. A specimen sample is dispensed using the metal probe. Next, the metal probe is washed with an active oxygen aqueous solution. A hydrophobic coating is used for the hydrophobic surface treatment. The active oxygen aqueous solution is ozone water or hydrogen peroxide water.
[Selection] Figure 1

Description

  The present invention relates to a method of using a metal probe used in an analyzer for analyzing a biological sample and an analyzer for analyzing the biological sample.

  In laboratory tests, specimen samples such as urine, serum, and plasma are analyzed. For analysis of sample samples, a method for obtaining a measurement value of an analysis item using a biochemical reaction between the sample sample and a reagent, and a method for obtaining a measurement value of an analysis item using an immune reaction between the sample sample and a reagent Various analysis methods such as a method using a DNA probe, a method of measuring DNA or the like by electrophoresis, and the like are used.

  In recent years, the sophistication of analysis methods, the volume of specimen samples, and the expansion of the measurement range have been remarkable. In order to cope with such a tendency and to obtain an accurate and reliable measurement value, it is necessary to sufficiently clean the instrument used for the analysis and prevent contamination by impurities.

  A sample sample dispensing probe is frequently used as an analytical instrument. By aspirating and discharging the specimen sample using the specimen sample dispensing probe, for example, the specimen is transferred from a container in which the specimen sample such as a blood collection tube is stored to a reaction container for reacting the specimen sample and the reagent. The sample can be moved.

  Specimen sample dispensing probes include metal reusable and plastic non-reusable disposable. Disposable probes are convenient but not economical because they do not need to be cleaned after each reuse. Reusable probes are economical, but need to be cleaned after each reuse. If the cleaning is insufficient, the probe to which the specimen sample residue is attached will be used next time. In this case, a so-called carry-over problem occurs in which the residue of the specimen sample is mixed into the newly collected specimen sample.

JP 2000-314739 A

  Conventionally, a cleaning method using pure water, a cleaning method using a detergent containing a surfactant, or the like is known as a cleaning method for a metal probe for sample sample dispensing. In the cleaning using pure water, there is a limit to increasing the efficiency of cleaning, and in the cleaning using a detergent, it is necessary to further wash the remaining detergent, which is not efficient. Also, instead of completely removing the residue of the specimen sample attached to the metal probe for specimen sample dispensing, the residue of the specimen sample attached to the probe is deactivated using active oxygen, and the residue of the specimen sample is substantially reduced. There is a method of removing from the measurement object. In this method, when the metal probe is repeatedly used, the residue of the inactivated specimen sample is accumulated on the surface of the metal probe. Therefore, this method is not suitable for long-term use.

  An object of the present invention is to provide means capable of easily and reliably cleaning a metal probe.

  According to the present invention, first, a hydrophobic surface treatment is applied to the surface of a metal probe. A specimen sample is dispensed using the metal probe. Next, the metal probe is washed with an active oxygen aqueous solution. A hydrophobic coating is used for the hydrophobic surface treatment. The active oxygen aqueous solution is ozone water or hydrogen peroxide water.

  According to the present invention, a metal probe can be easily and reliably cleaned.

  With reference to FIG. 1, the example of the usage method of the metal probe for specimen sample dispensing by this invention is demonstrated. The sample sample dispensing metal probe is made of, for example, stainless steel, and preferably has a constant inner diameter. First, in step S101, the surface of the metal probe is subjected to a hydrophobic surface treatment. The hydrophobic surface treatment agent used for the hydrophobic surface treatment may be any substance as long as it imparts hydrophobicity to the surface of the metal probe and is stable even when contacted with active oxygen. It may be a fluorine-based material used as a coating agent for spectacle lenses. As such a fluorine-based substance, for example, a silane coupling agent such as OPTOOL DSX (trade name) manufactured by Daikin Industries, Ltd. may be used. Thus, by performing the hydrophobic surface treatment, a hydrophobic treatment film having a thickness of 100 nm or less is formed on the surface of the metal probe.

  In step S102, a specimen sample is dispensed using a metal probe. That is, a metal probe is inserted into a container in which a specimen sample such as a blood collection tube is stored, and the specimen sample is aspirated. Next, the specimen sample is discharged into a container for reacting the specimen sample and the reagent. Since a hydrophobic treatment film is formed on the surface of the metal probe, the amount of the specimen sample that can be aspirated by the metal probe is smaller than when the hydrophobic surface treatment is not performed. The amount of the specimen sample remaining on the manufactured probe is also reduced.

  In step S103, the metal probe is washed with an active oxygen aqueous solution. The active oxygen aqueous solution may be any aqueous solution containing an active oxygen substance, and may be, for example, ozone water or hydrogen peroxide water. The half-life of ozone is shorter than other active oxygen substances. Therefore, it can be said that ozone water has a lower environmental load than other active oxygen substances. By using ozone water having an ozone concentration of 20 ppm or more, the carryover rate (the ratio of the sample sample used last time to the sample sample used this time) can be suppressed to 1 ppm or less. In addition, since ozone has a short half-life and decomposition proceeds rapidly, it is desirable to produce ozone water near the place of use and immediately before use. In order to perform cleaning using ozone water having an optimal ozone concentration, it is necessary to set the initial concentration of ozone in consideration of the production time and use time of ozone water.

  The half-life of hydrogen peroxide is longer than the half-life of ozone, and decomposition proceeds gradually. By using a hydrogen peroxide solution having a hydrogen peroxide concentration of 30 to 50 wt%, the carryover rate can be suppressed to 1 ppm or less.

  It has already been described that the amount of residual metal probe can be reduced by the hydrophobic surface treatment in step S101. The hydrophobic surface treatment further has an antioxidant effect and a cleaning effect on the metal probe. The antioxidant effect of the metal probe will be described. In step S103, since the metal probe is washed with an active oxygen aqueous solution, if there is no hydrophobic treatment film on the surface of the metal probe, the active oxygen comes into direct contact with the surface of the metal probe. Therefore, the metal probe is oxidized. However, when there is a hydrophobic treatment film on the surface of the metal probe, since the active oxygen is prevented from coming into direct contact with the surface of the metal probe, oxidation is suppressed.

  The cleaning effect will be described. If there is a hydrophobic treatment film on the surface of the metal probe, the specimen sample is difficult to adhere, that is, the adhesion of the specimen sample is reduced. Therefore, the metal probe can be easily cleaned in the cleaning process of the next step S103.

  Here, the method of using the metal probe for sample sample dispensing has been described. However, the method of use of the present invention can also be applied to the cleaning of reagent dispensing metal probes.

  With reference to FIG. 2, the example of the analyzer provided with the cleaning apparatus of the metal probe by this invention is demonstrated. The analyzer includes a sample container disk 11 having a large number of sample containers, a reagent container disk 12, 12 having a large number of reagent containers, a reaction container disk 13 having a large number of reaction containers, and a sample in the sample container as a reaction container. Sample dispensing probe 14 for dispensing into the reaction vessel, reagent dispensing probes 15 and 15 for dispensing the reagent in the reagent vessel into the reaction vessel, and a sample pump for sucking or discharging the sample with the sample dispensing probe 16. Reagent pumps 17 and 17, an interface 30, a control device 31, a keyboard 32, a printer 33, and a display device 34 for aspirating or discharging a reagent by a reagent dispensing probe. The probes 14 and 15 are formed of a stainless steel tube having an inner diameter of 0.3 mm.

  FIG. 3 shows the main part of the analyzer. The analyzer includes a stirring device 21 for stirring the sample and the reagent in the reaction container, a reaction container cleaning device 22 for cleaning the reaction container, and a reaction measuring device 23 for measuring the reaction between the sample and the reagent in the reaction container.

  FIG. 4 shows a metal probe cleaning device 24 provided in the analyzer. The metal probe cleaning device 24 contains ozone water produced by an ozone water production device. The sample dispensing probe 14 is cleaned by the metal probe cleaning device 24 after dispensing the sample in the sample container 1 to the reaction container.

  With reference to FIG. 5, the outline | summary of an ozone water manufacturing apparatus is shown. The ozone water production apparatus includes an ozone gas generator 51 that generates ozone, a regulation container 52 that stores ozone water, and a mixer 53 that mixes ozone water from the regulation container and ozone from the ozone gas generator. Initially, pure water is stored in the adjustment container 52. In the mixer 53, the pure water from the adjustment container 52 and the ozone from the ozone gas generator 51 are mixed to generate ozone water. This ozone water is returned to the preparation container 52. By repeating such circulation, the ozone concentration of the ozone water stored in the adjustment container 52 increases. When the ozone concentration of the ozone water in the adjustment container 52 reaches a predetermined value, it is supplied to the metal probe cleaning device 24.

  In order to confirm the effect of the present invention, Experimental Example 1 was performed. In Experimental Example 1, the cleaning method according to the present invention was performed using a stainless steel plate instead of the metal sample dispensing sample probe, and the amount of the specimen remaining on the stainless steel plate was measured. The stainless steel plate was used because it was assumed that the sample sample dispensing metal probe was made of stainless steel. Moreover, in order to evaluate the result of Experimental Example 1, Comparative Examples 1, 2, and 3 were implemented.

  First, a hydrophobic surface treatment was performed on the stainless steel plate to form a hydrophobic treatment film. The hydrophobic surface treating agent is a solution of OPTOOL DSX (trade name) manufactured by Daikin Industries, Ltd. having a concentration of 0.1 wt%. The stainless steel plate was immersed in the hydrophobic surface treatment agent at a speed of 1 mm / sec and held for 3 minutes. Next, the stainless steel plate was pulled up at a speed of 0.1 mm / sec. The stainless steel plate was left in a constant temperature room at 120 ° C. for 20 minutes and then taken out. Next, the stainless steel plate was subjected to ultrasonic cleaning for 20 minutes using Sumitomo 3M's cleaning liquid FC-72 (trade name). The surface roughness of the stainless steel plate thus subjected to the hydrophobic surface treatment was Ra = 110 nm.

  Next, the specimen sample was adhered to the surface of the stainless steel plate. As a specimen sample, a phosphate buffer containing a rabbit skeletal muscle-derived lactate dehydrogenase at a concentration of 2.6 mg / mL was used. Hereinafter, rabbit skeletal muscle-derived lactate dehydrogenase is simply referred to as a specimen. 60 μL of this specimen sample was dropped on a stainless steel plate and left for 30 minutes.

  Next, the stainless steel plate was washed with ozone water. The ozone water was manufactured by the ozone water manufacturing apparatus described with reference to FIG. When the ozone concentration of the ozone water in the adjustment container 52 reached 20 ppm or more, 30 mL of ozone water was quickly moved to the washing tank. A stainless steel plate was inserted into this washing tank. The specimen adhering to the surface of the stainless steel plate was washed with ozone water in the washing tank. The cleaning conditions at this time are as follows.

Initial liquid volume of the adjustment container 52: 5 L of pure water
Ozone generation amount of the ozone gas generator 51: 2 g / h
Cleaning time (immersion time of stainless steel plate in cleaning tank): 3 min
Washing temperature: room temperature

  The amount of the sample eluted in the ozone water in the washing tank was measured using the μ-BCA (micro BCA) method. The amount of the sample measured in this way was defined as the amount of the sample removed by washing. The amount of specimen remaining on the stainless steel plate was obtained by subtracting the amount of specimen removed by washing from the amount of specimen contained in the specimen sample dropped on the stainless steel plate.

  FIG. 6 shows the experimental conditions. In Comparative Example 1, the stainless steel plate was not subjected to a hydrophobic surface treatment. Moreover, it wash | cleaned with the pure water instead of wash | cleaning with ozone water. Except that the hydrophobic surface treatment was not performed and the surface was washed with pure water, it was the same as Experimental Example 1. In Comparative Example 2, the stainless steel plate was subjected to a hydrophobic surface treatment and washed with pure water instead of washing with ozone water. Except for the point washed with pure water, it is the same as Experimental Example 1. In Comparative Example 3, the stainless steel plate was not subjected to a hydrophobic surface treatment, but was washed with ozone water. Therefore, it is the same as Experimental Example 1 except that the hydrophobic surface treatment was not performed on the stainless steel plate.

  FIG. 7 shows the experimental results of Example 1. The vertical axis represents the amount of specimen remaining on the stainless steel plate. As shown in the figure, in the case of Comparative Example 1, the amount of the remaining specimen is the largest, that is, the cleaning effect is insufficient. The amount of the remaining specimen decreases in the order of Comparative Example 2 and Comparative Example 3. That is, the cleaning effect is increased. In the case of Experimental Example 1, compared with Comparative Examples 1, 2, and 3, the amount of the remaining specimen is extremely small, that is, the cleaning effect is large.

  In order to confirm the effect of the present invention, Experimental Example 2 was performed. In Experimental Example 2, the cleaning method according to the present invention was performed using a metal probe for dispensing specimen samples, and the carryover rate was measured. Moreover, in order to evaluate the result of Experimental Example 2, Comparative Examples 4, 5, and 6 were performed.

First, a hydrophobic surface treatment was applied to a metal probe to form a hydrophobic treatment film. The hydrophobic surface treating agent is a solution of OPTOOL DSX (trade name) manufactured by Daikin Industries, Ltd. having a concentration of 0.1 wt%. A metal probe is fixed to a syringe, an OPTOOL DSX solution having a concentration of 0.1 wt% is sucked at a flow rate of 5.3 × 10 ⁻¹ m / sec and held for 3 minutes, and then a flow rate of 1.8 × 10 ^−1. It discharged at m / sec. Next, the metal probe was removed from the syringe. The metal probe was left in a constant temperature room at 120 ° C. for 20 minutes and then taken out. Next, ultrasonic cleaning was performed on the metal probe for 20 minutes using a cleaning liquid FC-72 (trade name) manufactured by Sumitomo 3M.

Next, the specimen sample was attached to the surface of the metal probe. As a specimen sample, serum containing lactate dehydrogenase derived from rabbit skeletal muscle at a concentration of 5 × 10 ⁵ IU / L was used. Hereinafter, rabbit skeletal muscle-derived lactate dehydrogenase is simply referred to as a specimen. 12 μL of this specimen sample was dispensed by a metal probe, that is, sucked and discharged.

  Next, the metal probe was washed with hydrogen peroxide. That is, 12 μL of hydrogen peroxide solution having a concentration of 30 wt% was sucked and discharged by a metal probe.

  Finally, the carryover rate of the metal probe after washing was measured. First, 12 μL of physiological saline was dispensed with a washed metal probe. Next, the rabbit skeletal muscle-derived lactate dehydrogenase contained in the dispensed physiological saline was measured. Rabbit skeletal muscle-derived lactate dehydrogenase contained in the dispensed physiological saline is considered to be the residue of the specimen attached to the metal probe. The carryover rate was obtained by the following formula.

  (Carryover rate) (ppm) = (Concentration of specimen contained in physiological saline dispensed by metal probe after washing) / (Concentration of specimen contained in specimen)

  As shown in FIG. 8, in Comparative Example 4, the hydrophobic probe was not applied to the metal probe. Moreover, it wash | cleaned with the pure water instead of wash | cleaning with hydrogen peroxide solution. It is the same as Experimental Example 2 except that the hydrophobic surface treatment was not performed and the surface was washed with pure water. In Comparative Example 5, the metal probe was not subjected to a hydrophobic surface treatment, but washed with hydrogen peroxide. Similar to Experimental Example 2 except that the hydrophobic surface treatment was not performed. In Comparative Example 6, the metal probe was subjected to a hydrophobic surface treatment, but washed with pure water instead of hydrogen peroxide. Therefore, it is the same as Experimental Example 2 except that it is washed with pure water.

  As shown in FIG. 8, in the case of the comparative example 4, the carryover rate is the highest, that is, the cleaning effect is insufficient. The carryover rate decreases in the order of Comparative Example 5 and Comparative Example 6. That is, the cleaning effect is increased. In the case of Experimental Example 2, the carryover rate is extremely low as compared with Comparative Examples 4, 5, and 6, that is, the cleaning effect is large. In the case of Comparative Example 6, the carryover rate is relatively low. From this, it can be said that the carry-over rate is lowered by applying a hydrophobic surface treatment to the metal probe.

  The example of the present invention has been described above, but the present invention is not limited to the above-described example, and various modifications can be made by those skilled in the art within the scope of the invention described in the claims. It will be understood.

It is a figure which shows the example of the washing | cleaning method of the metal probes by this invention. It is a figure which shows the structure of the analyzer provided with the cleaning apparatus of the metal probe by this invention. It is a figure which shows the structure of the principal part of the analyzer provided with the cleaning apparatus of the metal probe by this invention. It is a figure which shows the structure of the washing | cleaning apparatus of the metal probe by this invention. It is a figure which shows the experimental result of Example 2 of the cleaning method of the metal probe by this invention. It is a figure which shows the conditions of the Example of the washing | cleaning method of the metal probe by this invention. It is a figure which shows the result of the Example of the cleaning method of the metal probe by this invention. It is a figure which shows the structure of an ozone water manufacturing apparatus. It is a figure which shows the conditions and result of the Example of the washing | cleaning method of the metal probe by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sample container, 2 ... Reagent container, 3 ... Reaction container, 11 ... Sample container disk, 12 ... Reagent container disk, 13 ... Reaction container disk, 14 ... Sample dispensing probe, 15 ... Reagent dispensing probe, 16 ... sample pump, 17 reagent pump, 21 ... stirring device, 22 ... reaction vessel cleaning device, 23 ... reaction measuring device, 24 ... metal probe cleaning device, 30 ... interface, 31 ... control device, 32 ... keyboard, 33 ... printer 34 ... Display device, 51 ... Ozone gas generator, 52 ... Adjustment container, 53 ... Mixer,

Claims (6)

  A metal probe comprising: applying a hydrophobic surface treatment to a surface of the metal probe; dispensing a specimen sample using the metal probe; and washing the metal probe with an active oxygen aqueous solution. How to use.   2. The method for using a metal probe according to claim 1, wherein the hydrophobic surface treatment uses a fluorine-based coating agent.   2. The method of using a metal probe according to claim 1, wherein the active oxygen aqueous solution is ozone water or hydrogen peroxide water.   A sample container disk having a plurality of sample containers; a reaction container disk having a plurality of reaction containers; a sample dispensing probe for dispensing a sample in the sample container to the reaction container; and And a cleaning device for cleaning the pouring probe with an active oxygen aqueous solution, wherein the sample dispensing probe is subjected to a hydrophobic surface treatment.   5. The analyzer according to claim 4, wherein the hydrophobic surface treatment is performed with a fluorine-based coating agent.   5. The analyzer according to claim 4, wherein the active oxygen aqueous solution is ozone water or hydrogen peroxide water.

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