JP2002031643A - Specimen measuring method using reagent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring method in which a tip can be cleaned without installing a cell exclusively used for cleaning and to provide a measuring method in which a liquid in a prescribed amount can be collected precisely by a dispensing tip. SOLUTION: At least one kind from among a reagent cell in which a reagent is housed and a diluent cell in which a diluent used to dilute a specimen is housed is prepared. A mixing cell in which the specimen or the diluted specimen is reacted with the reagent is prepared. The specimen is prepared. The reagent and/or the diluent in an amount exceeding an amount required for measurement are housed in the reagent cell and/or the diluent cell. The specimen or the diluted specimen and the reagent are dispensed into the mixing cell by the dispensing tip. The dispensing tip is cleaned by a liquid which remains in the reagent cell or the diluent cell.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dispensing a sample such as blood into a mixed cell and reacting it with a reagent to perform measurement such as component analysis.

[0002]

2. Description of the Related Art The operation of dispensing a sample or a reagent into a reaction container is mechanized for the purpose of preventing variations among operators, saving labor costs, and shortening measurement time.
Since such a dispensing device is expensive, the dispensing device main body is shared even when a plurality of types of reagents are used to measure a plurality of items.

In order to increase the complexity of this type of dispensing apparatus and to prevent contamination of the reagent due to mixing of the reagents, Japanese Patent Application Laid-Open No. 8-122336 discloses an optical measurement hole (hereinafter referred to as a measurement cell). A method of measuring with a single dispensing tip (referred to as a pipette in the same publication) using a cartridge provided with a holding section for holding a dispensing tip and a hole (hereinafter, a washing liquid cell) for accommodating a washing liquid. Is disclosed.

[0004] In the cartridge, a predetermined amount of a sample such as blood or body fluid is dispensed directly into a mixing cell after diluting the sample with a sample diluent present in a dilution cell, and then a predetermined amount of a reagent contained in the reagent cell is dispensed. It is used as a place where measurement is started by discharging into the mixing cell into which the sample has already been injected

In the cartridge, a single pipette is used for dispensing and diluting a sample, dispensing a reagent, and dispensing a washing solution and the like. The reason that contamination does not occur even though the dispensing operation is performed with one dispensing pipette is that the dispensing tip is washed with the washing liquid stored in the washing liquid cell in advance. The cleaning liquid cell also serves as a drain cell for storing the drain liquid after cleaning. If contamination does not occur with one dispensing tip, the dispensing tip is frequently replaced or a tip cleaning mechanism is unnecessary as in the conventional case, and thus there is an advantage that the measuring device can be downsized.

In general, immediately after the start of the measurement, including the measurement method described in JP-A-8-122336, a dispensing tip contained in a cartridge is attached to a nozzle, and a first sample or reagent is mounted. Etc. are sucked. In most cases, the first sample or reagent is aspirated without any pretreatment. Usually, silicon or the like is treated inside the dispensing tip in order to discharge the collected liquid without leaving it. When collecting low viscosity liquids,
Since the liquid is discharged neatly without the liquid remaining inside the dispensing tip, the liquid can be collected with high accuracy.

[0007]

However, Japanese Patent Application Laid-Open No. Hei 8-1
The cartridge disclosed in Japanese Patent No. 22336 requires a dedicated washing liquid cell for containing a dedicated washing liquid in order to wash the dispensing tip. If the cleaning is incomplete, contamination will occur. Therefore, it is necessary to perform cleaning at least to such an extent that contamination does not occur. Therefore, a plurality of cleaning liquid cells are required. Therefore, the size of the cartridge increases, and the operability deteriorates.

[0008] Also, immediately after the start of measurement, a new dispensing tip must be used as described above. However, when a highly viscous sample such as whole blood is aspirated, even if the inside of the dispensing tip is as described above. Even if silicon treatment is performed, an error occurs in the suction amount, and as a result, an error occurs in the measurement result. This is because while whole blood has two sides, hydrophilic and hydrophobic, the dispensing tip exhibits strong hydrophobicity, so it receives strong resistance in the suction process and is easily affected by viscosity. It seems to be a phenomenon that occurs. Therefore, a first object of the present invention is to provide a measurement method capable of cleaning a chip without providing a cell dedicated for cleaning.
A second object is to provide a measuring method capable of accurately collecting a predetermined amount of liquid with a dispensing tip.

[0009]

Means for Solving the Problems In order to solve the first problem, a measuring method of the present invention provides a solution containing a sample and a solution to be mixed with the sample to measure components in the sample. The method is characterized in that a cell and a mixed cell in which a sample and a reagent react are prepared, and a solution cell containing an amount of solution exceeding an amount necessary for measurement is stored in the solution cell, and then the following steps are performed in random order. (A) a step of dispensing a sample into a mixed cell using a dispensing tip; (B) a step of dispensing a required amount of the solution in the solution cell to the mixing cell with the same dispensing tip. (C) washing the same dispensing tip with the solution remaining in the solution cell; Here, the solution refers to, for example, a reagent and a diluent, and the solution cell refers to, for example, a reagent cell and a diluent cell.

[0010] According to the measuring method of the present invention, the dispensing tip is washed with an extra solution than the amount required for the measurement, so that there is no need to prepare a separate washing liquid. In addition, after dispensing an amount of reagent and / or diluent necessary for measurement, the dispensing tip can be washed in the reagent cell or diluent cell, so that a separate washing tank and a disposal tank need to be prepared. Nor.

If the drained liquid after washing is discarded in another cell not involved in the measurement without returning to the collected cell, washing can be repeated as long as the reagent or diluent remains. If the remaining diluent or reagent in the cell is less than one wash, after sucking all the remaining liquid, the diluent or reagent remaining in another cell is suctioned to make up and washed. Is also good. Then, it is not necessary to provide a cell dedicated to drainage, and an arbitrary cell can be set as needed. An arbitrary cell that has been set can also accommodate drainage a plurality of times as long as the capacity is allowed.

[0012] In order to solve the second problem, the measuring method of the present invention comprises the steps of:
The order of the steps (c) and (a), or the step (b),
Steps (a) and (c) are performed in this order.
By wetting the new chip with the reagent or the diluting liquid in this manner, a sample or a reagent to be aspirated next can be accurately collected. This makes it possible to reduce the difference between the dispensed volumes of a highly viscous whole blood specimen and a low-viscosity plasma specimen or serum specimen.

Further, by wetting a new dispensing tip in advance or after use, not only can a sample or a reagent to be sucked next be collected with high accuracy, but also when the dispensing tip is washed thereafter, the cleaning effect can be improved. Is also expected to be raised. This is probably because the silicon surface inside the dispensing tip is coated with the liquid for pre-cleaning.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a dispensing tip cleaning method according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a four-unit cartridge in which four cells used for dispensing are integrally connected, and a sample container.

The cartridge 1 can be made of plastic or glass such as polystyrene resin, acrylic resin, vinyl chloride resin or the like.
A material made of polystyrene resin, which is inexpensive, has good light transmittance, and is easy to handle, can be suitably used.

The cartridge 1 has a first mixing cell 2, a first reagent cell 3, a second mixing cell 4, and a second reagent cell 5 in order from the left end, and these cells are formed so as to be connected by integral molding. I have. In the first reagent cell 3 and the second reagent cell 5, more reagents A and B than necessary for the measurement
Are preliminarily inserted. In addition, cartridge 1
The sample container 6 placed near the sample container holds a sample in an amount required for measurement of a plurality of items.

All cells are sealed so that the contained liquid does not spill during transportation. As the sealant, aluminum foil, various polymer films or the like can be used alone or in a laminated form. The sealant can be opened by hand at the start of use, or can be broken by a breaker or the like before use.

When the measurement is started, first, a new dispensing tip is attached to the nozzle, and the reagent A contained in the first reagent cell 3 is sucked and discharged by the dispensing tip, and then necessary for the measurement. The amount of reagent A is sucked and discharged to the first mixing cell 2.
Next, the same dispensing tip aspirates an arbitrary amount of reagent B required for measurement from the second reagent cell 5 and discharges it to the second mixing cell 4. At this stage, the cartridge 1 has the first mixed cell 2 and the second mixed cell 4 as shown in FIG.
And a reaction tank for reagent B, and the first reagent cell 3 and the second reagent cell 5 become washing tanks.

Subsequently, a sample amount required for measurement is aspirated from the sample container 6 by the dispensing tip and the first mixed cell 2
And agitating by repeating suction and discharge several times with the dispensing tip to cause the reagent to react with the sample. Thereafter, the dispensing tip is washed by repeating suction and discharge of the reagent B remaining in the reagent cell 5 with the dispensing tip. The sample volume required for measurement is aspirated from the sample container 6 with the dispensing tip after washing and discharged to the second mixing cell 4, and the aspirating and discharging are repeated several times with the dispensing tip to agitate the reagent and the sample. Is reacted.

After a lapse of a predetermined time when the reaction is considered to be completed, the discoloration or turbidity change of the reagent accompanying the reaction is optically detected, and the concentration of the specific component in the sample is output. By adapting the new dispensing tip with the reagent B, the reagent B can be accurately collected, and the washing effect of the dispensing tip can be expected to increase. The reagent B used for washing is the remaining liquid in the second reagent cell 5 and is the same as the reaction liquid in the second mixed cell, so there is no risk of affecting the reaction.

Example 2 This is a comparison between the case where whole blood is collected using a new dispensing tip and the case where whole blood is collected after pre-washing the dispensing tip with a reagent or a diluent. This is an experiment to confirm whether whole blood was collected accurately.

In this example, 0, 5% saponin physiological saline was used as a sample diluent. First, a dispensing tip was attached to the tip of the nozzle, 10 μl of whole blood was directly sucked without pre-washing, and the whole blood inside the dispensing tip was ejected and weighed. Next, another new dispensing tip is attached to the tip of the nozzle, pre-washed by sucking and discharging 0% and 5% saponin physiological saline, and then 10 μl of whole blood is sucked and placed inside the dispensing tip. The whole blood was discharged, and the weight was measured with an electronic balance. Table 1 shows the results.

[0023]

[Table 1]

As shown in the table, a clear difference was observed between the case where the sample was collected with a new dispensing tip and the case where the sample was pre-washed with 0,5% saponin saline. Since the specific gravity of the blood was 1.07, the true weight of 10 μl was 0.0107
become. Those with pre-washing of the dispensing tip show a value close to the true value although there is variation. On the other hand, the value without the pre-wash shows a value far from the true value, and the whole blood can be accurately collected by pre-washing the inside of the dispensing tip.

Next, a cartridge for diluting a sample with a sample diluent will be described. As shown in FIG. 3 as a cross-sectional view,
The cartridge 11 is made of a transparent plastic or the like in the same manner as in the first embodiment, and is arranged in order from the left end.
2. It has a diluent cell 13, a first mixing cell 14, a first reagent cell 15, a second mixing cell 16, and a second reagent cell 17, and these cells are formed so as to be connected by integral molding. The diluent cell 13 contains a diluent for diluting the sample in a larger amount than necessary. Similarly, the first reagent cell 15 and the second reagent cell 17 each contain a reagent A and a reagent B in advance, respectively, in an amount larger than that required for measurement. A sample container 18 placed near the cartridge 11 contains whole blood, serum, or plasma as a sample to be measured.

In the actual measurement, first, the dispensing tip accommodating cell 1
The dispensing tip accommodated in 2 is mounted on the nozzle, and the sample diluent contained in the diluent cell 13 is aspirated and discharged to adapt the dispensing tip. Subsequently, a required amount of the same sample diluent is aspirated and discharged to the first mixing cell 14. Subsequently, a required amount of the same sample diluent is suctioned and discharged to the second mixing cell 16. Since the dilution ratio of the sample varies depending on the measurement item, the amount of the sample diluent and the amount of the sample differ depending on the measurement item.

Various kinds of samples are stored in the sample container 18, but when whole blood is stored, since time has elapsed since the blood was collected and the blood is separated into a blood cell layer and a plasma layer,
After agitating by repeating the suction and discharge with the dispensing tip, a predetermined amount is suctioned and discharged to the first mixing cell 14. Stirring of the diluted sample is performed by repeating suction and discharge of the dispensing tip.

Before the reagent A is aspirated by the dispensing tip, the first washing is performed with the remaining diluent. The cleaning method includes:
The suction and discharge are repeated several times with the remaining diluent. After the washing, a certain amount of the reagent A is sucked and discharged to the first mixing cell 14. Stirring is performed by repeating suction and discharge several times with the dispensing tip, and the reagent A and the diluted sample are reacted.

Next, the reagent A remaining in the first reagent cell 15
The suction and discharge are repeated to perform the second washing of the dispensing tip. A predetermined amount of the reagent B contained in the second reagent cell 17 is aspirated, discharged to the second mixing cell 16, and agitated by repeating suction and discharge several times to react the reagent B with the diluted sample. .

The first washing of the dispensing tip is performed with the sample diluent, and the second washing is performed with the remaining reagent A.
When the reagent A has any effect on the reaction by the reagent B, the reagent B is first collected and reacted in the second mixing cell 16, and then the dispensing tip is washed with the remaining reagent B, and the reagent A is washed. To perform the reaction in the first mixing cell 14. As described above, by performing washing with a solution that does not affect the reaction among the remaining solutions, the reliability of measurement data is improved. Whether or not the reaction is affected is determined by determining in advance how much the reagent used as the washing solution affects the next reaction, and determining the order of measurement and the order of the remaining reagents to be used. You should leave it.

[0031]

According to the present invention, since one dispensing tip can be used repeatedly, resources can be saved and no cost is required. The cartridge contains
Since there is no need to provide a washing liquid, a washing liquid cell, and a waste liquid cell, the cartridge itself can be downsized. Further, since a highly viscous sample such as whole blood can be dispensed with high accuracy, a measurement result with few errors can be obtained, which can greatly contribute to the field of clinical examination.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a cartridge illustrating an initial stage of a measurement method according to a first embodiment.

FIG. 2 is a cross-sectional view of a cartridge illustrating an intermediate stage of the measurement method according to the first embodiment.

FIG. 3 is a sectional view of a cartridge illustrating an initial stage of a measurement method according to a second embodiment.

[Explanation of symbols]

 1 Cartridge 2, 4 Mixing cell 3, 5 Reagent cell 6 Sample container

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G052 AA28 AB16 AD06 AD08 AD09 AD26 AD28 AD29 AD46 AD48 AD49 CA18 CA28 CA36 DA06 DA12 FC05 HC07 HC27 JA01 JA09 2G058 CA02 EB01 ED21 ED32 FA01 FA04 FB06 FB07 FB14 FB19

Claims (7)

[Claims] 1. A sample, a solution cell containing a solution mixed with the sample for measuring a component in the sample, and a mixed cell in which the sample and the reagent react are prepared, and the amount required for the measurement is prepared. A sample measuring method, wherein the following steps are performed in any order after a solution cell containing an amount of the solution exceeds 3. (A) a step of dispensing a sample into a mixed cell using a dispensing tip; (B) a step of dispensing a required amount of the solution in the solution cell to the mixing cell with the same dispensing tip. (C) washing the same dispensing tip with the solution remaining in the solution cell; 2. The method according to claim 1, wherein said solution is a reagent. 3. The method according to claim 1, wherein said solution is a diluent. 4. The method according to claim 1, wherein the solution cell and the solution cell are two or more types, respectively, and the solution cell in the step (c) is at least one type selected from the first solution cell and the second solution cell. The method described in. 5. The method of claim 4, wherein said first solution and said first solution cell are a reagent and a reagent cell, respectively, and said second solution and said second solution cell are a diluent and a diluent cell. 6. The method according to claim 1, wherein the steps (b), (c) and (a) are performed in this order. 7. The method according to claim 1, wherein the steps (b), (a) and (c) are performed in this order.