JP2011125313A - Apparatus and method for inspecting fresh milk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for inspecting fresh milk simply and quickly at a low cost. <P>SOLUTION: The apparatus for inspecting fresh milk comprises: a means (a), which has a surface to which surfactant adheres, to release myeloperoxidase from somatic cells of the fresh milk by letting the fresh milk come in contact with the surfactant; a means (b) for measuring the concentration of the released myeloperoxidase; and a means (c) for calculating the number of somatic cells in the fresh milk from the concentration of the myeloperoxidase. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an apparatus and method for examining raw milk of mammals, particularly dairy cows.

  In the livestock industry, there is an increasing need for early and detailed diagnosis of livestock conditions, such as the diagnosis of livestock diseases, injuries, and diagnosis of the effects of administered drugs. The need is particularly high for infectious diseases. Analyzing raw milk from livestock is an important and effective means for diagnosing dairy livestock such as cattle, sheep and goats.

  Injuries, inflammation, and infectious diseases often show an increase in somatic cells in raw milk, such as neutrophils. This tendency is particularly remarkable in mastitis.

  Mastitis is the biggest problem among dairy cattle catastrophes. Mastitis is one of the world's most incurable diseases because it is a disease that is susceptible and extremely difficult to cure. The number of somatic cells in the raw milk of dairy cows affected by mastitis is 300,000 or more, and 3 million in some cases, while normal dairy cows usually have 10,000 to 100,000 / mL. There are many cases of chronic mastitis more than 1 / mL. Measuring the number of somatic cells is cumbersome, and the equipment that realizes it is expensive, so the inspection of raw milk is usually carried out after being collected in a large tank (in many cases, transported to another inspection organization, etc.) . If this happens, not only will the detection be delayed and the amount of damage will increase, but if it is detected that the number of somatic cells in the sampled raw milk exceeds the specified value, the milk will be discarded in tank units or penalized to the dairy farmer. Is imposed. Therefore, early detection and treatment of mastitis is desired. In the detection and diagnosis of these mastitis, the method for analyzing raw milk of the domestic animals is very effective.

  The image identification method is a method in which neutrophils in raw milk are stained, lipid particles and neutrophils are identified and automatically measured by a camera. In the image identification method, since the problem of light shielding by lipid particles occurs, the volume of raw milk is 0.1 mL or less, and measurement is performed by fixing the raw milk in a thin flat space. However, there has been a problem that the somatic cell count measurement by the automatic cell count instrument by the image identification method is very expensive. In addition, there has been a problem that the measurement of smearing with an optical microscope takes too much time. In addition, since a small amount of sample is used, there is a problem that measurement errors are likely to occur.

  Therefore, it has been proposed to measure the amount of active oxygen released from somatic cells mixed in the analysis of raw milk by the luminol chemiluminescence method (see Patent Document 1).

  The luminol chemiluminescence method is a method in which a luminol reagent is excited by active oxygen released from neutrophils, the amount of chemiluminescence is detected and amplified, and the amount of active oxygen is quantified. This is a technique that can detect the number of neutrophils that gather in conjunction with bacterial invasion with high sensitivity over a wide range from the initial stage of bacterial invasion to early mastitis.

  However, the mastitis diagnostic apparatus using the luminol chemiluminescence method has a problem in practicality because the apparatus is expensive and requires a time of 10 minutes or more to obtain a certain amount of light.

Japanese Patent Laid-Open No. 2000-041696

  It is an object of the present invention to provide an apparatus that is inexpensive and can easily and quickly inspect raw milk. Another object of the present invention is to provide a method capable of examining raw milk simply and quickly at a low cost.

The present invention comprises a surface (a) having a surface to which a surfactant is attached, and releasing myeloperoxidase from somatic cells in the raw milk by contacting the raw milk with the surfactant;
Means (b) for measuring the concentration of the released myeloperoxidase;
And a means (c) for calculating the number of somatic cells in raw milk from the concentration of the myeloperoxidase.

The present invention also comprises a step (a) of contacting my milk with a surfactant to release myeloperoxidase from somatic cells in the milk.
Measuring the concentration of the released myeloperoxidase (b);
And a step (c) of calculating the number of somatic cells in the raw milk from the concentration of the myeloperoxidase.

  According to the apparatus of the present invention, an apparatus capable of inspecting raw milk simply and quickly can be provided at low cost. According to the method of the present invention, raw milk can be inspected simply and quickly at low cost.

It is a top view which shows an example of the raw milk test | inspection apparatus of this invention. It is a perspective view which shows the sensor which comprises the raw milk test | inspection apparatus shown in FIG. It is the III-III sectional view taken on the line of FIG. It is a top view which shows the sensor which abbreviate | omitted the cover plate. It is a block diagram of the raw milk test | inspection apparatus shown in FIG. It is a top view which shows another example of the raw milk test | inspection apparatus of this invention.

  First, the raw milk test | inspection apparatus of this invention is demonstrated. The raw milk test apparatus of the present invention has a surface to which a surfactant is attached, means (a) for releasing myeloperoxidase (MPO) from somatic cells in the raw milk by bringing the raw milk into contact with the surfactant. Means (b) for measuring the concentration of the released MPO, and means (c) for calculating the number of somatic cells in the raw milk from the concentration of MPO. In the present specification, the term “somatic cell” refers to a myeloid cell that possesses a large amount of the MPO, and particularly refers to neutrophils, monocytes, and macrophages. Refers to these numbers.

  In the present invention, the surfactant means a compound having a hydrophilic part and a lipophilic part in one molecule. The surfactant is preferably water-soluble because it is easily dispersed in raw milk. The surfactant may be either an ionic surfactant or a nonionic surfactant. Examples of the ionic surfactant include an anionic surfactant, a cationic surfactant, and an amphoteric surfactant.

  Examples of the anionic surfactant include sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium dodecyl-N-sarcosinate, sodium cholate, sodium deoxycholate, sodium taurodeoxycholate and the like.

  Examples of cationic surfactants include hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, didecyldimethylammonium chloride, didecyldimethylammonium bromide, dodecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, octadecyltrimethylammonium chloride, Octadecyltrimethylammonium bromide, tetradecylammonium bromide, dodecylpyridinium chloride, hexadecylpyridinium chloride, hexadecylpyridinium bromide, 1-laurylpyridinium chloride, tetradecyltrimethylammonium bromide, benzalkonium chloride, benzalkonium bromide, benzethonium chloride, etc. Can be mentioned.

  Examples of amphoteric surfactants include 3-[(3-colamidopropyl) dimethylammonio] -1-propanesulfonic acid, 3-[(3-colamidopropyl) dimethylammonio] -2-hydroxy-1 -Propanesulfonic acid, palmitoyl lysolecithin, dodecyl-N-betaine, dodecyl-β-alanine and the like.

  Examples of nonionic surfactants include octyl glucoside, heptyl thioglucoside, decanoyl-N-methyl glucamide, polyoxyethylene dodecyl ether, polyoxyethylene heptamethylhexyl ether, polyoxyethylene isooctyl phenyl ether, polyoxy Examples include ethylene nonyl phenyl ether, polyoxyethylene fatty acid ester, sucrose fatty acid ester, polyoxyethylene sorbitol ester and the like.

  The surfactant is preferably a cationic surfactant because it has a high ability to release MPO from somatic cells in raw milk, and may be a cationic surfactant containing a halogen ion as a counter ion. More preferred.

  The raw milk to be tested is raw milk of mammals, preferably raw milk of animals (eg, dairy cows, goats, etc.) bred as livestock, and more preferably raw milk of dairy cows from the viewpoint of demand.

  As a means (a) having a surface to which a surfactant is attached and bringing MPO from somatic cells in the raw milk by bringing the raw milk into contact with the surfactant, there is a space portion, A member containing a surfactant is mentioned, and specifically, a container in which the surfactant is applied to the inner surface, an inspection space (inspection room) in which the surfactant is applied to the inner surface, and the like.

  The amount of the surfactant is preferably 0.05 to 10% with respect to the volume of the space (volume of containers, inspection spaces, etc.).

  The means (b) for measuring the concentration of the released MPO is not particularly limited, and may be a means for directly measuring the MPO concentration or a means for indirectly measuring it. A preferred means for indirectly measuring the concentration of MPO is a means for measuring the concentration of hypohalous acid.

  Neutrophils contain MPO. Oxygen in raw milk is reduced to a superoxide anion by activated NADPH oxidase, and the superoxide anion is converted to hydrogen peroxide by superoxide dismutase (SOD). From this hydrogen peroxide and halogen ions, hypohalous acid is generated by the action of MPO. At this time, the concentration of generated hypohalous acid is proportional to the concentration of MPO. Therefore, the concentration of MPO is indirectly obtained by measuring the concentration of hypohalous acid.

  The concentration of hypohalous acid can preferably be measured electrochemically. Specifically, when a voltage of about −0.2 to −0.6 V is applied to raw milk, hypohalous acid causes a reduction reaction, and a reduction current peculiar to hypohalous acid flows. Since this reduction current is proportional to the hypohalite ion concentration, the concentration of hypohalous acid can be determined from the reduction current value (or the voltage value obtained by converting the reduction current). Therefore, the means (b) includes, for example, an electrode including a working electrode and a counter electrode, a circuit for applying a voltage, and a minute current measuring device.

  An example of the means (c) for calculating the number of somatic cells in raw milk from the concentration of MPO is an arithmetic device. The computing device includes a computing unit having a CPU and the like, and a storage unit having a memory, a hard disk, and the like. Since the MPO concentration correlates with the neutrophil concentration, it also correlates with the number of somatic cells. Therefore, it is possible to create a calibration curve between the MPO concentration or the parameter representing the MPO concentration and the number of somatic cells, the calibration curve is stored in the storage unit, and the calculation unit stores the calibration curve in the calibration curve. Based on this, the number of somatic cells is calculated. Examples of the parameter representing the MPO concentration include a current value (particularly, a reduction current value of hypohalous acid), a voltage value (particularly, a value obtained by converting the reduction current of hypohalous acid into a voltage), and the like.

  The raw milk test apparatus may further include means (d) for determining mastitis infection of livestock from the number of somatic cells. An example of the means (d) for determining mastitis infection in livestock from the number of somatic cells is an arithmetic device. The computing device includes, for example, a computing unit and a storage unit, and inputs a threshold for the number of somatic cells that serves as a reference for mastitis infection into the storage unit in advance, thereby calculating the mastitis infection of domestic animals from the measured number of somatic cells. Judgment. As the arithmetic device, the arithmetic device of means (c) may be used as it is, or another arithmetic device may be used.

  The raw milk inspection apparatus of the present invention preferably has means for notifying the result. Examples of the means include a display unit such as a monitor and a lamp, and a speaker.

  The concentration of hypohalous acid in raw milk depends on pH. Within the normal raw milk pH range, the number of somatic cells can be measured with little influence of pH, but the raw milk test apparatus of the present invention has a pH measuring means (eg, pH meter). May be.

  According to the raw milk inspection apparatus of the present invention, an apparatus capable of inspecting the number of somatic cells in raw milk simply and quickly can be provided at low cost. In addition, the apparatus can be made compact.

  Although this invention is a raw milk test | inspection apparatus, it can also be applied as a mastitis diagnostic apparatus.

The present invention also provides, from another aspect, a step of bringing MPO into contact with raw milk and a surfactant to release MPO from somatic cells in the raw milk;
Measuring the concentration of the released MPO (b);
And a step (c) of calculating the number of somatic cells in the raw milk from the concentration of the MPO.

  The raw milk inspection method of the present invention can be preferably carried out using the above-described raw milk inspection device.

  Step (a) can be performed by mixing raw milk and the above-mentioned surfactant in a container, a laboratory, or the like. The surfactant may be applied to the inner surface of a container, a laboratory, or the like, or may be added to a container, a laboratory, or the like containing raw milk. The surfactant is as described above.

  In step (b), the concentration of MPO may be measured directly or indirectly. For example, the concentration of MPO can be indirectly measured by measuring the concentration of hypohalous acid. The concentration of hypohalous acid can be measured by an electrochemical method.

  For raw milk, a calibration curve can be created by determining the somatic cell value by the conventional method and the MPO concentration by the steps (a) and (b). In step (c), the number of somatic cells can be calculated based on this calibration curve. As the MPO concentration, for example, parameters representing the MPO concentration such as current value (especially the reduction current value of hypohalous acid) and voltage value (especially a value obtained by converting the reduction current of hypohalous acid into voltage) are used. It may be used.

  The raw milk test method of the present invention may further include a step (d) of determining mastitis infection of domestic animals from the number of somatic cells. As an example, when examining raw milk of dairy cows, the number of somatic cells in raw milk of healthy dairy cows is 10,000 to 100,000 / mL, while raw milk of dairy cows that are likely to be infected with mastitis The number of somatic cells is 300,000 cells / mL or more. Therefore, when the measured number of somatic cells is 300,000 cells / mL or more, it can be determined that the milk is dairy cow suspected of being infected with mastitis.

  According to the raw milk inspection method of the present invention, raw milk can be inspected simply and quickly at low cost.

  The present invention is a method for examining raw milk, but can also be applied as a mastitis diagnostic method.

  Hereinafter, the specific example of the raw milk test | inspection apparatus of this invention is shown.

  In FIG. 1, the specific example of a raw milk test | inspection apparatus is shown. The raw milk inspection apparatus 1 </ b> A includes a sensor 2, a connector 5, and a main body 6, and the sensor 2 is detachable from the main body 6 at the connector 5. As will be described later, the sensor 2 includes electrodes, and by making the sensor 2 detachable, the measurement can be easily repeated simply by replacing the sensor 2.

  Next, the configuration of the sensor 2 will be described in detail with reference to FIGS. The sensor 2 is of a substantially rectangular plate type having an examination room 20 for holding raw milk, and the plate type sensor can easily optimize the electrode arrangement and the like. Raw milk is introduced into the examination room 20 by capillary action. The volume of the examination room 20 is preferably 0.01 to 5 mL, and more preferably 0.05 to 1 mL. A more preferable volume of the examination room 20 is 0.1 to 0.3 mL.

  Specifically, the sensor 2 includes a substantially rectangular base plate 21 and three working electrodes 31, a reference electrode 32, and a counter electrode 33 supported by one surface (one surface in the thickness direction) 21 a of the base plate 21. An electrode and a substantially rectangular cover plate 22 fixed to one surface 21a of the base plate 21 with the electrodes 31 to 33 interposed therebetween are provided. In the following description, for convenience of explanation, one of the longitudinal directions of the base plate 21 (upper right direction in FIG. 2) is referred to as the front, and the other (lower left direction in FIG. 2) is referred to as the rear. (Lower right direction in FIG. 2) is called the right side, and the other (upper left direction in FIG. 2) is called the left side.

  The width of the cover plate 22 is the same as the width of the base plate 21, but the length of the cover plate 22 is set shorter than the length of the base plate 21 so as to expose the rear end portion of the one surface 21 a of the base plate 21. Yes. The size of the base plate 21 is, for example, 60 mm long, 30 mm wide, and 1 mm thick. The size of the cover plate 22 is, for example, 50 mm long, 30 mm wide, and 3 mm thick.

  The material of the base plate 21 and the cover plate 22 is not particularly limited as long as it is insulative. For example, acrylic resin, polylactic acid resin, polyglycolic acid resin, styrene resin, polyolefin resin , Methacryl-styrene copolymer resin (MS resin), polycarbonate resin, polyester resin such as polyethylene terephthalate, polyvinyl alcohol resin, ethylene-vinyl alcohol copolymer resin, thermoplastic elastomer such as styrene elastomer, vinyl chloride Resin, silicone resin such as polydimethylsiloxane, vinyl acetate resin, polyvinyl butyral resin, and the like. The material of the base plate 21 is preferably selected as appropriate in consideration of adhesion with an electrode material described later, and the material of the cover plate 22 is preferably selected as appropriate in consideration of adhesion with the base plate 21. .

  A groove 23 is formed in the cover plate 22 so as to open to the end surface of the cover plate 22 along the base plate 21, and the inspection chamber 20 is configured by the groove 23 and one surface 21 a of the base plate 21. The examination room 20 is automatically filled with raw milk from the opening 23a by capillary action. That is, the opening 23 a of the groove 23 constitutes an introduction port to the examination room 20. In order to utilize the capillary phenomenon, the width of the groove 23 is preferably 1 to 50 mm, the depth is 0.05 to 5 mm, and the length is preferably 2 to 100 mm, more preferably the width of the groove 23 is 3 to 30 mm. The depth is 0.1 to 3 mm and the length is 10 to 70 mm. For example, the width of the groove 23 may be 10 mm, the depth may be 0.5 mm, and the length may be 40 mm.

  The groove 23 can be formed by machining, injection molding, or the like, and the base plate 21 and the cover plate 22 can be joined by heat fusion, laser fusion, solution adhesion technique, or the like. By applying a method established as such an industrial production technique, the accuracy of the volume of the examination room 20, that is, the accuracy of the amount of raw milk introduced into the sensor 2 can be increased. Thereby, if it is the same raw milk, the number of the neutrophils in the laboratory 20 can be made constant, and it becomes possible to improve the measurement accuracy of the number of somatic cells.

  In this specific example, since the capillary phenomenon is used, it is possible to fill the examination room 20 with the raw milk in a short time, for example, within 5 seconds, simply by immersing the end of the sensor 2 on the opening 23a side in the raw milk. . In addition, the sensor 2 does not necessarily need to utilize a capillary phenomenon, and an examination room may be provided by a through hole that penetrates the cover plate in the thickness direction. At this time, the sensor 2 corresponds to the spotting method.

  The working electrode 31, the reference electrode 32, and the counter electrode 33 are arranged in the left-right direction, and each extends linearly in the front-rear direction from the rear end of the base plate 21 to a predetermined position. In this specific example, a circular first electrode part (positive electrode part) 31a is provided at the tip of the working electrode 31, and a circular second electrode part (negative electrode part) larger than the first electrode part 31a is provided at the tip of the counter electrode 33. ) 33a is provided. Also, the tip 32a of the reference electrode 32 has a small circular shape. The first electrode portion 31 a and the second electrode portion 33 a and the tip 32 a of the reference electrode 32 all face the internal space of the examination room 20. Moreover, the part which is not covered with the cover plate 22 in each electrode 31-33 comprises the wide terminal parts 31b-33b, and the sensor 2 is inserted in the connector 5 by these terminal parts 31b-33b. When attached, it is electrically connected to a terminal (not shown) of the connector 5.

  The surfactant 4 is applied on the surface 31c of the first electrode portion 31a. The surfactant 4 may be applied to a place in the examination room 20 other than on the surface 31c of the first electrode portion 31a. For example, the surfactant 4 may be applied in the vicinity of the opening 23 a in the examination room 20. As described above, the surfactant is applied so as to face the inside of the examination room, so that the surfactant is attached to the surface, and the milk and the surfactant are brought into contact with each other, so that MPO from the somatic cells in the raw milk. Means (a) for releasing

The reference electrode 32 is used as a reference electrode. When a voltage of −0.2 V, for example, is applied between the working electrode 31 and the reference electrode 32, hypohalous acid causes a reduction reaction on the first electrode portion 31 a, and the working electrode 31 and the counter electrode 33 Current flows between them. By measuring the amount of current flowing between the working electrode 31 and the counter electrode 33, it is possible to measure the amount of MPO in raw milk, and thus the number of somatic cells in raw milk. In order to efficiently detect the reduction current, the area of the second electrode part 33a is preferably larger than the area of the first electrode part 31a. Here, “the area of the second electrode portion 33a” and “the area of the first electrode portion 31a” are the areas when the second electrode portion 33a and the first electrode portion 31a are viewed from a direction orthogonal to the base plate 21. Say. Area of the first electrode portion 31a is preferably 0.7～500Mm ^2, more preferably 4~250mm ^2.

  As a method for forming the electrodes 31 to 33, vapor deposition, sputtering, electrolytic plating, electroless plating, silk screen printing, metal paste injection, or the like can be used. By adopting such an industrially established method, the electrodes 31 to 33 can be formed with high accuracy, and the reproducibility of measured values can be improved in mass production. Examples of the conductive material used for the electrode include gold, silver, silver chloride, platinum, copper, aluminum, and SUS. In this specific example, the working electrode 31 is made of gold, the reference electrode 32 is made of silver / silver chloride, and the counter electrode 33 is made of platinum so as to be suitable for reduction of hypohalous acid.

  Preferably, the width of each electrode 31 to 33 is 0.05 to 20 mm, the length is 5 to 100 mm, and the thickness is 0.003 to 300 μm. More preferably, the width of each electrode 31 to 33 is 0.1 to 30 mm. 10 mm, length is 10 to 50 mm, and thickness is 0.02 to 200 μm.

  In order to increase the surface area of the electrode, for example, an uneven structure or the like may be provided in the electrode portion.

  Next, the configuration of the apparatus main body 6 will be described in detail with reference to FIG. The apparatus body 6 calculates the number of somatic cells contained in the raw milk based on the current that flows when a voltage is applied to the working electrode 31. Specifically, the apparatus main body 6 applies a voltage between the power source 65, the working electrode 31 and the reference electrode 32 via a circuit, and detects a current flowing between the working electrode 31 and the counter electrode 33. A circuit 62, a current-voltage conversion circuit 63 that converts the detected current into a voltage, and a calculation device 64 that calculates the number of somatic cells from the voltage value are displayed. The number of somatic cells calculated by the calculation device 64 is displayed. Displayed on the part 61.

  The power source 65 may be an internal power source such as a battery or a battery, or may be an external power source such as a household power source. The current detection circuit 62 is configured by a switching element or the like. The current-voltage conversion circuit 63 includes a current-voltage conversion element and an operational amplifier that amplifies the voltage.

  In this way, means (b) for measuring the concentration of MPO emitted from the electrodes 31 to 33, a circuit (not shown) for applying a voltage between the electrodes, the current detection circuit 62, and the current-voltage conversion circuit 63 are configured. .

  The computing device 64 includes a computing unit (such as a CPU) and a storage unit (such as RAM and ROM). The arithmetic device 64 corresponds to means (c) for calculating the number of somatic cells in raw milk from the concentration of MPO. The storage unit stores a calibration curve that associates the voltage value with the number of somatic cells, and the arithmetic device 64 calculates the number of somatic cells according to the voltage value sent from the current-voltage conversion circuit 63. In this specific example, since the current is very small, the voltage value obtained by amplifying the current after converting it to a voltage is used. However, since the current value can be obtained using this voltage value, the current value is used. Is also possible. The calculation device 64 can also function as means (d) for determining mastitis infection of domestic animals from the number of somatic cells by inputting a threshold value of the number of somatic cells indicating mastitis infection to the storage unit. When a plurality of types of sensors 2 having different sensitivities are used, a calibration curve may be stored in the storage unit for each sensor 2.

  Next, a method for measuring the number of somatic cells using the raw milk test apparatus 1A will be described. The sensor 2 is attached to each connector 5 arranged in the sampling container for raw milk. Next, the on button 6a is pressed to turn on the power switch. When milking is started, the measurement button 6c is pushed to make it measurable. When raw milk is filled in the sampling container, raw milk is filled into the examination room 20 from the opening 23a of the sensor 2 by capillary action. Then, the surfactant in the examination room 20 comes into contact with the raw milk and is dispersed in the raw milk, and MPO is released from the neutrophils in the raw milk. Hypohalous acid is generated by the action of MPO, and the current flowing through reduction of this hypohalous acid is sent to the device body 6 to calculate the number of somatic cells. The calculated number of somatic cells is displayed on the display unit 61. It is also possible to input a reference somatic cell number into the apparatus main body 6 in advance, and when the calculated somatic cell number exceeds the reference somatic cell number, the lamp can be turned on or notified by voice.

  When milking and the measurement of the number of somatic cells are completed, the milker and the raw milk sampling container are washed, and the sensor 2 used for the measurement is replaced with a new sensor 2 in preparation for the next measurement.

  The raw milk inspection apparatus 1A of this specific example is suitable for batch measurement, and the examiner etc. quickly uses the raw milk sampled by the dairy farmers, the raw milk collected and delivered to the certification association, etc., the raw milk sampled in units of tanks, etc. Effective when measuring. The raw milk inspection apparatus 1A can have outer dimensions of, for example, a height of 120 mm, a width of 80 mm, and a weight of about 300 g so as to be excellent in portability.

  FIG. 6 shows another specific example of the raw milk inspection apparatus of the present invention. This raw milk inspection apparatus 1B is composed of four sensors 2 corresponding to the number of dairy cow quarters and an apparatus main body 6 connected to these sensors 2 by a cable 71. The apparatus main body 6 is provided with four display units 61 corresponding to each sensor 2 and various push buttons 6a to 6c.

  This configuration is suitable for continuous measurement in which the number of somatic cells is measured simultaneously with milking, and the number of somatic cells can be measured for a plurality of raw milk at a time.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited to these Examples.

[Testing of somatic cell count in raw milk samples]
Raw milk was sampled from 2 healthy cattle (a, b) and 3 cattle infected with mastitis (c, d, e). From the result of introducing the raw milk sample into the cell counter and counting the number of somatic cells in a certain range, the number of somatic cells present in the raw milk sample per certain volume, more specifically, the number of neutrophils was calculated. The number of somatic cells in raw milk is a: 50,000 / mL, b: 20,000 / mL, c: 330,000 / mL, d: 580,000 / mL, e: 960,000 / mL there were.

[Fabrication of sensor]
A 1 mm thick acrylic plate was cut to a length of 60 mm and a width of 30 mm to form a base plate. Next, the base plate was masked, and a working electrode (gold) and a counter electrode (platinum) were formed in a pattern shown in FIG. 4 using a sputtering apparatus (manufactured by Shinko Seiki, model SDH10311). Specifically, the working electrode has a diameter of 6 mm and the counter electrode has a diameter of 8 mm. Further, the reference electrode (silver / silver chloride) was formed by applying a silver / silver chloride ink (manufactured by BAS Inc.) after masking the base plate.

  Next, 40 μL of 5% benzalkonium chloride (BKC) aqueous solution as a surfactant was applied on the working electrode. Next, an acrylic resin (Kuraray Co., Ltd., Parapet GH-S) is used, and a groove having a length of 40 mm, a width of 10 mm, and a depth of 0.5 mm, a length of 50 mm, a width of 30 mm, and a thickness of 3 mm is obtained by an injection molding method. The cover plate was formed.

  Next, using a laser resin welding machine (Miyachi Technos, model: ML-5220B), the base plate and the cover plate were welded to obtain a sensor. This sensor was connected to a main body having a power source, a voltage application circuit, and a minute current measuring device.

[Measurement of MPO concentration in raw milk]
2 mL of the raw milk samples a to e were introduced into the produced sensor, a voltage of −0.2 V was applied to the working electrode, and recording of the current value flowing between the working electrode and the counter electrode was started. Table 1 shows the maximum current value after 5 seconds from the start of measurement.

  From Table 1, it can be seen that the current value increases as the number of somatic cells in raw milk increases. The current value is based on the current that flows when the hypohalous acid in raw milk is electrically reduced, and hypohalous acid is generated by the action of MPO. It is an index of MPO concentration. MPO is released from neutrophils by the action of a surfactant. Therefore, according to this invention, it turns out that the number of somatic cells in raw milk can be calculated | required simply and rapidly, and raw milk can be test | inspected.

  The present invention is used for examining whether or not a mammal infected with mastitis is raw milk, and can also be used for diagnosing mastitis infection in mammals.

DESCRIPTION OF SYMBOLS 1A, 1B Raw milk test | inspection apparatus 2 Sensor 20 Test room 21 Base plate 21a Surface 22 Cover plate 23 Groove 23a Opening 31 Working electrode 31a 1st electrode part 31c Surface 32 Reference electrode 32a Tip 33 Counter electrode 33a 2nd electrode part 4 Surfactant 5 Connector 6 Device body

Claims (6)

Means (a) having a surface to which a surfactant is attached, and contacting the milk with the surfactant to release myeloperoxidase from somatic cells in the milk;
Means (b) for measuring the concentration of the released myeloperoxidase;
A raw milk test apparatus comprising means (c) for calculating the number of somatic cells in raw milk from the concentration of the myeloperoxidase.   The raw milk test | inspection apparatus of Claim 1 which further contains the means (d) which determines the mastitis infection of domestic animals from the said somatic cell count.   3. The raw milk inspection apparatus according to claim 1, wherein the means (b) is a means for measuring the concentration of hypohalous acid.   The raw milk test | inspection apparatus of Claim 3 which measures the density | concentration of the said hypohalous acid by an electrochemical method.   The raw milk inspection apparatus according to any one of claims 1 to 4, wherein the surfactant is a cationic surfactant containing a halogen ion as a counter ion. Contacting the raw milk with a surfactant to release myeloperoxidase from somatic cells in the raw milk;
Measuring the concentration of the released myeloperoxidase (b);
A method for examining raw milk, comprising a step (c) of calculating the number of somatic cells in raw milk from the concentration of the myeloperoxidase.

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