JPH06289031A - Method and device for biochemical analysis - Google Patents

Abstract

PURPOSE:To improve measurement accuracy by measuring absorbance of produced material corresponding to an inspected component in two sample reaction liquid for absorption wave length and calculating the concentration or active value of the inspected component from the measured value. CONSTITUTION:A reaction vessel 4 as a measuring cell are annularly arranged around a reaction table 2 and when the table 2 rotates a reaction line 6 moves vessels 5 one by one at every certain time. Around the table 2, provided are a sampling mechanism 8, first and second reagent dispensing mechanism 10, 12 and a multiwave light meter for measuring absorbance and the like. The sampling mechanism 8 has a sample line where sample bottles are arranged along the circumference of the sample table 14, and a sample dispensing pipetten 16. The table 2 rotation is controlled so that the reaction vessels 4 which absorbance is compared and judged, are positioned at the sample distribution points for every analysis cycle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analysis method performed as a clinical biochemical test in a medical institution and the like, and an automatic analyzer for performing the method.

[0002]

2. Description of the Related Art In an analysis by an automatic biochemical analyzer, when a sample has an extremely high concentration or an extremely high activity, an operator dilutes the sample and reexamines it, or a dilution line provided in the automatic analyzer. Automatically dilutes the sample for re-inspection, or reduces the amount of sample to be re-inspected, or newly aliquots the sample into the reaction container and automatically dilutes it with the diluent. A re-examination will be conducted. On the contrary, the concentration or activity value of the sample may be too low. In that case, a predetermined analysis accuracy cannot be obtained.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for increasing the measurement accuracy and an automatic analyzer equipped with the function, especially when the concentration or activity value of a sample is too low. To do.

[0004]

In the present invention, a judgment step for comparing the absorbance or the change in absorbance with the measurement lower limit value and the measurement upper limit value is provided in the process from the start of the reaction to the final measurement. The reaction container after the determination step is positioned at the sample dispensing position so that the sample can be additionally injected after the determination step. The amount of additional sample is determined within the range in which the final absorbance or change in final absorbance after addition does not exceed the upper limit of measurement.

In the biochemical analysis method of the present invention, a predetermined amount of a liquid sample and a liquid reagent for analyzing a test component in the sample are poured into a reaction container and reacted for a fixed time under a constant temperature condition. For one reaction solution, the absorbance at the absorption wavelength of the test component or the product corresponding to the test component or its variation is measured, and when the value does not reach the predetermined measurement lower limit, the measurement upper limit is set. An additional amount of the same sample within a range not exceeding is added to the sample first reaction liquid to further react,
Regarding the sample second reaction solution after the addition of the sample, the absorbance or the amount of change in the absorption wavelength of the product of the test component or the product corresponding to the test component is measured, and from the measured value, the concentration of the test component or Calculate the activity value.

In order to perform the additional injection of the sample, in one embodiment of the automatic analyzer of the present invention, the sample portion is placed on or around a reaction line formed by annularly arranging a plurality of reaction vessels also serving as measurement cells. In a biochemical automatic analyzer equipped with at least an injector, a reagent dispenser, and an absorptiometer for measuring the reaction, the reaction line is the sample dispensing position of the reaction container after a certain time after dispensing the sample and the reagent into the reaction container. The control unit of the sample dispenser corresponds to the test component of the sample 1st reaction liquid after the fixed time after dispensing the sample and the reagent into the reaction container, or the test component thereof. Compare the absorbance at the absorption wavelength of the product to be measured or its change amount with the measurement lower limit value and the measurement upper limit value, and if the measurement lower limit value is not reached, the expected absorbance or its change amount does not exceed the measurement upper limit value. Sample in reaction solution And a additional dispensing control unit to perform the additional dispensing of the sample and the same sample by Petter.

In order to carry out additional injection of the sample, in another embodiment of the automatic analyzer of the present invention, the sample dispenser has a structure in which the movement locus of the pipettor intersects the reaction line at two intersections. The intersection point is the main dispensing position for performing sample dispensing for preparing the first measurement sample first reaction solution, and the other intersection point is the sub-dispensing position for the reaction container after a certain time has elapsed after the sample first reaction solution preparation, In the control part of the sample dispenser, the substance to be tested of the first reaction liquid of the sample after a certain time after the sample and the reagent are dispensed into the reaction container at the main dispensing position, or a substance corresponding to the analyte Absorbance at the absorption wavelength of or its change amount is compared with the measurement lower limit value and the measurement upper limit value, and if the measurement lower limit value is not satisfied, the expected absorbance or its change amount does not exceed the measurement upper limit value at the sub-dispensing position. Sample 1st reaction liquid and the sample by the sample pipettor Reaction of the main dispensing position of the analysis cycle in which one sample is additionally dispensed and only one of the sample dispensing positions can be dispensed within one analysis cycle, and the sample is additionally dispensed to the sub-dispensing position. It is provided with an additional dispensing control unit that delays the analysis condition assigned to the container backward by one analysis cycle and performs analysis processing.

[0008]

When the absorbance value or absorbance change value of the sample first reaction solution is less than or equal to the predetermined measurement lower limit value, the sample is added.
The additional dispensing amount of the sample shall be a predetermined amount, and if it is expected that the measurement upper limit value will be exceeded when a predetermined amount of sample is added, the sample addition amount shall not exceed the measurement upper limit value. Adjust to reduce. When a sample is added, the reagent blank value and the measurement upper limit value of the sample second reaction liquid to which the sample is added are corrected in consideration of the change in the liquid amount due to the addition of the sample.

FIG. 1 shows an example in which the present invention is applied to the endpoint method. 1 and 2 show the case where the absorbance increases with the reaction, these examples can also be applied to the case where the absorbance decreases, and in that case, in FIGS. The inequality sign is reversed.

In FIG. 1, the sample volume v
Then, the first reagent having a reagent blank value of Ab ₁ is dispensed as the reagent charge VR ₁ . At that time, the absorbance As ₁ of the mixed solution of the sample and the first reagent is measured. Next, the reagent blank value is A
Dispense the second reagent of b ₂ by the reagent amount VR ₂ . After the second reagent is dispensed, the absorbance As ₂ of the reaction solution after a certain time has elapsed is measured. The absorbance As ₂ is compared with the measurement upper limit value AUL, and when it exceeds the measurement upper limit value AUL, an “ultrahigh value” is output, and the sample is diluted and the retest is performed by a known method.

When the measured absorbance value As ₂ is less than or equal to the measurement upper limit value AUL, As ₂ is compared with the measurement lower limit value ALL, and if it is greater than or equal to the measurement lower limit value ALL, then the measured value As at that time
_{Using 2} , the concentration is calculated by the following equation (1). C = (As ₂ −Ab ₂ ) × K ₁ (1)

When the measured absorbance As ₂ is smaller than the lower limit value ALL, the same sample is additionally injected into the reaction solution. A predetermined amount is set as the additional amount v ′. Then, the final expected absorbance Ai when the predetermined sample amount v ′ is added is calculated by the following (2). Ai = (As ₂ −Ab ₂ ) × {(v + v ′) / (v + v ′ + VR ₁ + VR ₂ )} / {v / (v + VR ₁ + VR ₂ )} (2) When the predicted absorbance Ai is less than or equal to the measurement upper limit value AUL If there is, the sample of the set sample amount v'is dispensed. If Ai exceeds the measurement upper limit value AUL, the additional sample amount v'decreases to (v'-1), (v'-2), ... Dispense the largest sample volume of v ′ that satisfies the equation (3). (As ₂ −Ab ₂ ) × {(v + v ′) / (v + v ′ + VR ₁ + VR ₂ )} / {v / (v + VR ₁ + VR ₂ )} ≦ AUL (3)

The absorbance As ₃ of the reaction solution is measured a predetermined time after the addition of the sample. If As ₃ is less than or equal to the measurement upper limit value AUL, the concentration is calculated by the following equation (4) and output. C = (As ₃ −Ab ₃ ) × K ₂ (4) Here, the reagent blank value Ab ₃ is calculated by correcting Ab ₂ by the following equation (5) due to the change in the sample amount. The concentration conversion coefficient K _{2 is} also calculated by correcting K ₁ by the following equation (6) due to the change in the sample amount. _{Ab 3 = Ab 2 × {v} / (v + VR 1 + VR 2)} / {(v + v ') / (v + v' + VR 1 + VR 2)} (5) K 2 = K 1 × {v / (v + VR 1 + VR 2) } / {(v + v ' ) / (v + v' + VR 1 + VR 2)} (6)

When the absorbance measurement value As ₃ after adding the sample exceeds the upper limit measurement value AUL, the concentration cannot be calculated with the measurement value As ₃ , so the absorbance As ₂ before the sample addition is used. The density is calculated by the equation (1) and output.

Next, an example in which the present invention is applied to the rate method will be described with reference to FIG. Samples dispensed amount corresponding sample volume v, it refers to the first reagent in the reagent blank value Ab ₁ only reagent amount VR ₁ minute measuring the absorbance As ₁ of the reaction solution. Then, the second reagent is dispensed by the reagent amount VR ₂ and the rate is measured until time tf. The change in the reagent blank value at this time is (ΔAbf
/ Δt), the absorbance of the sample reaction solution is Asf, and the absorbance change (ΔAsf / Δt).

The absorbance Asf is compared with the measurement upper limit value AUL '. The measurement upper limit value AUL ′ is derived from the value AUL set as the rate measurement upper limit absorbance by the following equation (7). AUL ′ = AUL + (As ₁ −Ab ₁ ) Vc (7) Vc is a liquid amount correction coefficient and is represented by the following equation. Vc = (v + VR ₁ ) / (v + VR ₁ + VR ₂ ) When the absorbance Asf exceeds the upper limit of measurement AUL ′, an “ultra high value” is output, and the sample is retested by a known method.

The absorbance measurement value Asf is the measurement upper limit value AUL '.
In the following cases, Asf is compared with the measurement lower limit value ALL '. The measurement lower limit value ALL ′ is derived by the following equation (8) from the value ALL set as the rate measurement lower limit absorbance. ALL ′ = ALL + (As ₁ −Ab ₁ ) Vc (8) If the absorbance measurement value Asf is not less than the measurement lower limit value ALL ′, the measurement value Asf is used to calculate the concentration or activity value C according to the following equation (9). Is calculated. C = {([Delta] Asf / [Delta] t)-([Delta] Abf / [Delta] t)} * Kf (9) Kf is a conversion coefficient of the concentration or the activity value when the sample amount is v.

Absorbance measurement value Asf is the measurement lower limit value ALL '.
If smaller, inject the same sample into the reaction solution. A predetermined amount is set as the additional amount v ′. Then, the expected absorbance Ai at the final measurement time when the predetermined sample amount v ′ is added is calculated as
0). Ai = Asf + {(ΔAsf / Δt) − (ΔAbf / Δt)} × {(v + v ′) / (v + v ′ + VR ₁ + VR ₂ )} / {v / (v + VR ₁ + VR ₂ )} × Δte / Δtf (10) If the expected absorbance Ai is equal to or less than the measurement upper limit value AUL ′, the sample having the set sample amount v ′ is dispensed. If Ai
Exceeds the upper limit of measurement AUL ', the additional sample amount v
′ Is (v'-1), (v'-2), ... (both ≥
The sample amount of the largest v ′ satisfying the following expression (11) is gradually dispensed. [Asf + {(ΔAsf / Δt) − (ΔAbf / Δt)} × {(v + v ′) / (v + v ′ + VR ₁ + VR ₂ )} / {v / (v + VR ₁ + VR ₂ )} × Δte / Δtf] ≦ AUL ′ (11)

The rate measurement is performed from the addition of the sample to the final measurement time te. At the last measurement time te,
The reagent blank value change is (ΔAbe / Δt), the absorbance of the sample reaction solution is Ase, and the absorbance change is (ΔAse / Δt). The absorbance Ase at the final measurement time te is compared with the upper limit absorbance AUL ″ for rate measurement. AUL '' is the sample volume (v +
v ′) is the upper limit absorbance for the modified rate measurement, which is calculated by the following equation (12). AUL ″ = ALL + (As ₁ −Ab ₁ ) Vc × {(v + v ′) / (v + v ′ + VR ₁ + VR ₂ )} / {v / (v + VR ₁ + VR ₂ )} (12) Absorbance Ase is AUL ″ or less If so, the concentration or activity value C is calculated and output by the following equation (13). C = {(ΔAse / Δt) − (ΔAbe / Δt)} × Ke (13) where (ΔAbe / Δt) is a corrected reagent blank value in the sample amount (v + v ′), and is represented by the following equation (14) ( ΔAbf / Δt) is calculated,
Ke is the concentration (or activity value) in the sample amount (v + v ')
It is a conversion coefficient and is calculated by correcting Kf by the following equation (15). (ΔAse / Δt) = (ΔAbf / Δt) × {v / (v + VR ₁ + VR ₂ )} / {(v + v ′) / (v + v ′ + VR ₁ + VR ₂ )} (14) Ke = Kf × {v / (v + VR) ₁ + VR ₂ )} / {(v + v ′) / (v + v ′ + VR ₁ + VR ₂ )} (15)

If the absorbance Ase at the final measurement time te after adding the sample exceeds the upper limit of measurement AUL ″, the concentration or activity value cannot be calculated from the change in absorbance (ΔAse / Δt). Using the change in absorbance (ΔAsf / Δt) before adding the sample, the concentration or activity value is calculated and output according to the equation (9).

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 schematically shows an analysis unit in an automatic analyzer according to an embodiment. Around the reaction table 2, reaction vessels 4 also serving as measuring cells are arranged in a ring shape, and the reaction table 2 rotates counterclockwise as indicated by an arrow so that the reaction line 6 opens the reaction vessels 4 at regular intervals (several seconds). Move them one by one counterclockwise. The reaction table 2 is driven intermittently, for example, in one analysis cycle (one rotation +
Rotate 1 pitch) or (half rotation + 1 pitch).

Other than the sample sampling mechanism 8, the reagent dispensing mechanism 10 for the first reagent, and the reagent dispensing mechanism 12 for the second reagent, which are not shown in the figure, are further provided around the reaction table 2. A multi-wavelength photometer for measuring the absorbance of the reaction liquid in the reaction container, a cleaning mechanism for cleaning the reaction container after the reaction is completed,
A stirring mechanism for stirring the reaction liquid in the reaction container after the reagent is dispensed is provided. The sample sampling mechanism 8 includes a sample line in which sample bottles are arranged along the circumference of a sample table, and a sample dispensing pipettor 16 for dispensing a sample from the sample line into a reaction container at a sample dispensing position of a reaction line 6. Is equipped with.

The rotation of the reaction table 2 is such that the reaction container in which the measurement upper limit absorbance and the measurement lower limit absorbance are compared and determined for the first reaction liquid of the sample in which the sample and the reagent are injected into the regenerated reaction container which has been washed and dried. Are controlled to position at the sample dispensing position for each analysis cycle. At the sample dispensing position, a new sample is dispensed or an additional sample is dispensed into a reaction solution having an absorbance not higher than the lower limit of measurement of the sample first reaction solution.
FIG. 4 schematically shows an analysis unit in an automatic analyzer according to another embodiment.

In FIG. 4, the movement path of the sample dispensing pipettor 16 of the sample sampling mechanism 8 is 2 on the reaction line 6.
It is configured to move across the points P1 and P2. Of the two intersections P1 and P2 on the reaction line 6, one intersection P1 is the main dispensing position for performing sample dispensing for preparing the first reaction sample first reaction solution, and the other intersection P2 is the sample first reaction. This is a sub-dispensing position when a sample is added to the reaction container after a fixed time after the liquid preparation.

The control unit of the sample sampling mechanism 8 is provided with an additional dispensing control unit, and the additional dispensing control unit is
In the analysis cycle, only one of P1 and P2 sample dispensing positions can be dispensed, and it is assigned to the reaction container at the main dispensing position of the analysis cycle for additionally dispensing the sample to the sub-dispensing position P2. The analysis conditions are controlled so that the analysis processing is delayed by one analysis cycle backward.

[0026]

In the present invention, in the process from the start of the reaction to the final measurement, the absorbance or the absorbance change is compared with the measurement lower limit value and the measurement upper limit value, and when the absorbance or the absorbance change is less than the measurement lower limit value, Since the sample is added to the reaction container and the measurement is continued, it is possible to solve the problem that the concentration or activity value of the sample is too low and the measurement accuracy is lowered. Since the analysis reagent is used only for one measurement, the amount of reagent used can be smaller than that in the case where the retest is performed. Since expensive reagents are often used in biochemical analysis, the operating cost of this analysis method and analyzer becomes economical. Further, it is possible to deal with the problem more promptly than the conventional reinspection method.

[Brief description of drawings]

FIG. 1 is a flowchart showing an operation when the method of the present invention is applied to an endpoint method.

FIG. 2 is a flowchart showing the operation when the method of the present invention is applied to the rate method.

FIG. 3 is a schematic plan view showing an analysis unit of one embodiment.

FIG. 4 is a schematic plan view showing an analysis unit of another embodiment.

[Explanation of symbols]

 2 Reaction Table 4 Reaction Vessel 6 Reaction Line 8 Sample Sampling Mechanism 10, 12 Reagent Dispensing Mechanism 14 Sample Table 16 Sample Dispensing Pipettor P Sample Dispensing Position P1 Main Dispensing Position P2 Sub Dispensing Position

Claims (3)

[Claims] 1. A sample first reaction liquid obtained by injecting a predetermined amount of a liquid sample and a liquid reagent for analyzing a test component in the sample into a reaction container and allowing the liquid to react for a fixed time under a constant temperature condition. The absorbance or the amount of change in the absorption wavelength of the produced substance corresponding to the component or its test component is measured, and when the value does not reach the predetermined measurement lower limit value, the same sample within the range not exceeding the measurement upper limit value is measured. The additional amount is added to the sample first reaction liquid to further react, and the absorbance at the absorption wavelength of the product of the test component or the product corresponding to the test component of the sample second reaction liquid after the addition of the sample or A biochemical analysis method comprising measuring the amount of change and calculating the concentration or activity value of the test component from the measured value. 2. A sample dispenser, a reagent dispenser, and at least an absorptiometer for measuring the reaction are provided on or around a reaction line formed by annularly arranging a plurality of reaction vessels also serving as measurement cells. In the biochemical automatic analyzer described above, the reaction line moves so as to position the reaction container at a sample dispensing position after a fixed time after dispensing the sample and the reagent into the reaction container, and controls the sample dispenser. In the section, the lower limit of measurement is the absorbance at the absorption wavelength of the test component of the first reaction liquid of the sample or the product corresponding to the test component after a certain time after the sample and the reagent are dispensed into the reaction container. If the measured absorbance is below the measurement lower limit and the measured lower limit is exceeded, the expected absorbance or its variation does not exceed the measurement upper limit. To perform Biochemical automatic analyzer, characterized in that it comprises a pressurized dispensing controller. 3. A sample dispenser, a reagent dispenser, and at least an absorptiometer for measuring a reaction are provided on or around a reaction line formed by annularly arranging a plurality of reaction vessels also serving as measurement cells. In the biochemical automatic analyzer described above, the sample dispenser has a structure in which the movement trajectory of the pipettor intersects the reaction line at two intersections, and one of the intersections is used for preparing the first reaction sample first reaction solution. The main dispensing position for sample dispensing, the other intersection is the sub-dispensing position for the reaction container after a certain time has elapsed after the preparation of the first reaction solution of the sample, and the control unit of the sample dispenser is equipped with the main dispensing unit. The lower limit of the measurement or the absorbance at the absorption wavelength of the test component of the sample first reaction liquid or the product corresponding to the test component after a certain time after dispensing the sample and the reagent into the reaction container at the position Compare with the upper limit of measurement, and if the lower limit of measurement is not reached Is to cause the sample first reaction solution to perform additional dispensing of the same sample as the above sample by the sample pipetter at the sub-dispensing position within a range in which the expected absorbance or its change amount does not exceed the upper limit of measurement. Dispensing is possible only at one of the sample dispensing positions, and the analysis condition assigned to the reaction container at the main dispensing position of the analysis cycle that additionally dispenses the sample at the sub-dispensing position is delayed by one analysis cycle. An automatic biochemical analyzer characterized by comprising an additional dispensing control unit for performing an analysis process.