JPH07104344B2 - Standard solution for clinical examination - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a standard solution for clinical tests or a reaction indicator solution for setting a calibration coefficient, which is used in the measurement of serum components.

[0002]

2. Description of the Related Art Standard solutions for clinical tests are used as standards when measuring inorganic substances such as calcium and magnesium or nitrogen-containing components such as uric acid and creatinine. For example, it is an aqueous solution containing calcium, magnesium, creatinine, urea, uric acid, glucose and the like at a predetermined concentration.

The reaction indicator solution for setting the calibration coefficient is, for example, glucose, 4-nitrophenol, 4-nitroaniline, 2-chloro-4-nitrophenol, 5-amino-2-.
It is an aqueous solution containing a reaction indicator substance such as nitrobenzoic acid at a predetermined concentration, and determines the calibration coefficient (also called unit conversion coefficient, device constant, K factor) of measuring instruments such as automatic analyzers used in clinical tests. It is used to The calibration coefficient obtained by using this is to obtain a measured value based on the rate of change in absorbance per unit time, for example, alkaline phosphatase (ALP), leucine aminopeptidase (LAP), γ-glutamyl transpeptidase (γ -GTP) is used as a coefficient for correcting the difference between the measured value and the true value in the measurement of enzyme activity.

In recent years, with the development of automatic analyzers, clinical tests are generally performed by automatic analyzers. This automatic analyzer has an advantage that it is economical because the amount of the sample or the test reagent solution to be collected is small, but it also has a problem due to the small amount of the sample to be collected. That is, the problem is that the accuracy of the sampling amount differs between the serum, which is the main sample in the clinical examination, and the standard solution for clinical examination and the reaction indicator solution for setting the calibration coefficient. This is because serum and these solutions have different properties (specifically, specific gravity and viscosity), and the effect of this is in clinical tests using an automatic analyzer with a small sample collection volume of about several μl. In particular, there is a high possibility that the difference between the measured value calculated based on the values obtained by using these in the inspection and the true value becomes large.

As a method for solving this problem, it has been proposed to add, for example, glycerin or polyvinyl alcohol (hereinafter abbreviated as PVA) to these solutions (inspection and technology, vol. 17, No. 2, 190). -193,1989, 17th Japan Society for Clinical Laboratory Automation, 178,1985). However, even with these methods, it is impossible to make both the specific gravity and the viscosity of these solutions equal to those in serum at the same time, and it is difficult to expect that the accuracy of the collected amount will be equal to that of serum. Further, the method of adding glycerin cannot be said to be a preferable method in terms of the influence on the measured value due to cross contamination, since glycerin is also an error-causing substance in the measurement of triglyceride. Therefore, under the present circumstances, it is desired to develop a standard solution for clinical tests and a reaction indicator solution for setting a calibration coefficient, which have the same specific gravity and viscosity as serum.

[0006]

The present invention has been made in view of the above-mentioned circumstances, and in particular, in the measurement of serum components using an automatic analyzer, serum used for obtaining an accurate measurement value An object of the present invention is to provide a standard solution for clinical tests and a reaction indicator solution for setting a calibration coefficient, which have the same viscosity and specific gravity.

[0007]

According to the present invention, a clinical test is characterized in that the viscosity and the specific gravity of polyethylene glycol having an average molecular weight of 400 or less (hereinafter abbreviated as "PEG") are adjusted to be equivalent to serum. It is an invention of a standard solution for use or a reaction indicator solution for setting a calibration coefficient.

That is, the inventors of the present invention provide a standard solution for clinical tests or a reaction indicator solution for setting a calibration coefficient (hereinafter abbreviated as “standard solution for clinical tests”) with a viscosity and a specific gravity equivalent to those of serum. Intensive research was conducted to find an inactive substance that can be added and does not affect the reaction system of clinical tests, and PEG having a specific average molecular weight is the most suitable substance for that purpose. This has led to the completion of the present invention.

The PEG used in the present invention preferably has an average molecular weight of about 200 to 400. The concentration used varies depending on the type of other components contained in the standard solution for clinical tests, but it is usually 12 to 1 for PEG200 in the standard solution for clinical tests.
7 (v / v)%, 12-16 (v / v)% with PEG300, PEG
The range of 400 is about 12 to 14 (v / v)%.

In the present invention, as the PEG, those having a specific average molecular weight within the above-mentioned average molecular weight range may be used alone or in admixture of two or more kinds. Further, the standard solution for clinical examination of the present invention may contain a buffering agent, a preservative, a stabilizer, etc. which are usually contained in these solutions in addition to the standard substance and the reaction indicator substance. Needless to say. The concentrations of these components other than PEG in the standard solution for clinical tests and the like may be appropriately selected from the concentration range usually used in this field.

The standard solution for clinical examination of the present invention may be prepared, for example, as follows. That is, 1 selected from among PEGs having the above-mentioned average molecular weights
Or two or more species such as calcium, magnesium,
Standard liquid substances for clinical tests such as creatinine, urea, uric acid, glucose, etc., such as glucose, 4-nitrophenol, 4-nitroaniline, 2-chloro-4-nitrophenol, 5-amino-2-nitrobenzoic acid, etc. It is easily prepared by adding it to a solution containing a reaction indicator substance for setting a calibration coefficient and, if necessary, a buffer, a preservative, a stabilizer, etc., and dissolving it so that the viscosity and specific gravity become the same as serum. be able to.

Since the standard solution for clinical examination of the present invention has the same viscosity and specific gravity as the serum sample, the accuracy of the amount of collection is equivalent to that when the serum sample is used. Therefore, by using these to measure the components in serum, more accurate measurement becomes possible.

In the field of clinical examination, PEG has various uses, for example, a reaction accelerator in the immunoturbidimetric reaction and HD.
It is used as a fractionating agent in L-cholesterol measurement. However, when this is used as a viscosity and specific gravity adjusting agent for a standard solution for clinical tests and a reaction indicator solution for setting a calibration coefficient, it is completely unexpected that specific gravity and viscosity equivalent to serum can be imparted to these solutions. Was that.

By adding and dissolving commercially available albumin such as bovine serum albumin (hereinafter abbreviated as BSA) or human serum albumin, a standard solution for clinical examination having a specific gravity and viscosity equivalent to that of serum can be obtained. Although it can be prepared, these albumins often contain enzymes and nitrogen-containing components to be measured, and there are many problems in using them for the purpose of the present invention. Hereinafter, the present invention will be described more specifically with reference to Examples and the like, but the present invention is not limited thereto.

[0015]

EXAMPLES Experimental Example 1. Measurement of viscosity and specific gravity of various thickener aqueous solutions Ion-exchanged water has an average molecular weight of 200, 300, 400, 600, 100
0,6000 or 20000 PEG, glycerin, BSA, PV
An aqueous solution was prepared by adding 1 to 20% of each of A500 and polyvinylpyrrolidone (hereinafter abbreviated as PVP) K30, and the viscosity and the specific gravity were measured. The viscosity is measured with a B type (B8L type) viscometer (manufactured by Tokyo Keiki), and the specific gravity is measured with a standard specific gravity meter (JIS B-75-2).
The value at 25 ℃ was measured by 5). The results are shown in Table 1. In the table, the concentrations of PEG200, 300, 400, 600 and glycerin are v / v%, the others are w / v%, and the specific gravity is g / cm.
^{At 3} , the viscosities are expressed in centipoise (CP), respectively. The viscosities and specific gravities of pooled human sera measured under the same conditions were viscosity: 1.71 and specific gravity: 1.024.

[0016]

[Table 1]

As is clear from Table 1, it is found that a solution having both viscosity and specific gravity equivalent to human serum can be obtained by using PEG200, 300 and 400. It should be noted that even though BSA is used, a solution having a viscosity and a specific gravity equivalent to that of human serum has been obtained. However, BSA often contains contaminant enzymes and the like, and for the purpose of the present invention. There is a problem to use. Further, in the solution to which PVA 500 or PVP K30 was added, neither the viscosity nor the specific gravity was the same as human serum in some cases.

Example 1. Preparation of Reaction Indicator Solution for Setting Calibration Factor A solution containing 15% of PEG200 and having a concentration of 4-nitrophenol of 1.3 mM, 3.2 mM or 6.5 mM, and a reaction indicator for setting calibration coefficient of the present invention are prepared. It was a solution. Experimental Example 1. The viscosity and the specific gravity were determined in the same manner as in. The results are shown in Table 2.

Comparative Example 1. Example 1 except that PEG was omitted
1.3 mM, 3.2 mM, and 6.5 mM 4-nitrophenol solutions and were prepared in the same manner as in, and Experimental Examples 1. The viscosity and the specific gravity were determined in the same manner as in. The results are shown in Table 2.
Are also shown.

[0020]

[Table 2]

As is clear from Table 2, it is understood that by adding an appropriate amount of PEG200, a reaction indicator solution for setting a calibration coefficient whose viscosity and specific gravity are equivalent to those of human serum can be obtained.

Example 2. A solution containing 15% PEG200 and 150 mg / dl glucose was prepared and used as a standard solution for clinical examination. The viscosity and the specific gravity were measured in Example 1. The values obtained were similar to those of human serum when measured in the same manner as in. Reference example 1. Sampling accuracy by automatic analyzer (sample) Example 1. Reaction indicator solution for calibration coefficient measurement prepared in 1., and Comparative Example 1. Prepared in 4-
A nitrophenol solution and a sample were used. (Reagent) A first reagent and a second reagent of Alkaline Phosphatase II-HA Test Wako (manufactured by Wako Pure Chemical Industries, Ltd.) were used. (Operation method) Toshiba automatic analyzer TBA-30R, sample 5μ
Add 300 μl of the first reagent solution and 75 μl of the second reagent solution to
The operation of measuring the absorbance at 4 nm and the sub wavelength of 500 nm was repeated 10 times, and the maximum value (Max), the minimum value (Min), the standard deviation (SD) and the coefficient of variation (CV%) of the obtained absorbance were obtained. However, CV
(%) = SD / average value × 100. The results are shown in Table 3.

[0023]

[Table 3]

As is apparent from Table 3, it can be seen that the coefficient of variation is remarkably reduced by using the reaction indicator solution for setting a calibration coefficient of the present invention, that is, the accuracy of sample collection is improved. In addition, Example 2. The clinical test standard solution of the present invention obtained in, and the examination of the sample collection accuracy for an aqueous solution containing only 150 mg / dl glucose was carried out based on the above method, and the clinical test standard solution of the present invention was used. It was found that the coefficient of variation was obviously smaller, that is, the accuracy of the sample collection amount was better.

[0025]

INDUSTRIAL APPLICABILITY As described above, the present invention provides a standard solution for clinical tests and a reaction indicator solution for setting a calibration coefficient, which has a specific gravity and viscosity equivalent to that of serum, which was not obtained by the conventional method. However, if the measurement is performed by an automatic analyzer using these, a more accurate measurement value can be obtained, which is a great invention that contributes to the industry.

Claims (4)

[Claims] 1. A standard solution for clinical tests or a reaction indicator solution for setting a calibration coefficient , wherein viscosity and specific gravity are adjusted to be equivalent to serum by polyethylene glycol having an average molecular weight of 400 or less . 2. Polyethylene glycol having an average molecular weight of 2
The standard solution for clinical examination or the reaction indicator solution for setting a calibration coefficient according to claim 1, which is 0 to 400. 3. The standard solution for clinical examination according to claim 1, wherein the standard solution for clinical examination is a standard solution of calcium, magnesium, creatinine, urea, uric acid or glucose. 4. A reaction indicator for setting a calibration coefficient is glucose, 4-nitrophenol, 4-nitroaniline, 2-
The reaction indicator substance solution for setting a calibration coefficient according to claim 1, which is chloro-4-nitrophenol or 5-amino-2-nitrobenzoic acid.