JP2000166596A - Reagent for measuring urea nitrogen and measurement of urea nitrogen - Google Patents

Reagent for measuring urea nitrogen and measurement of urea nitrogen

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Publication number
JP2000166596A
JP2000166596A JP10374988A JP37498898A JP2000166596A JP 2000166596 A JP2000166596 A JP 2000166596A JP 10374988 A JP10374988 A JP 10374988A JP 37498898 A JP37498898 A JP 37498898A JP 2000166596 A JP2000166596 A JP 2000166596A
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Japan
Prior art keywords
urea nitrogen
reagent
reaction
measuring
ammonia
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JP10374988A
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Japanese (ja)
Inventor
Kozo Kawasaki
幸造 川崎
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Shino Test Corp
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Shino Test Corp
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Publication of JP2000166596A publication Critical patent/JP2000166596A/en
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  • Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a reagent and method for measuring urea nitrogen, capable of accurately measuring urea nitrogen in a specimen by preventing ammonia from making a positive error to a measured value arise and by completely terminating a coupled reaction due to an isocitrate dehydrogenase. SOLUTION: This reagent for measuring urea nitrogen includes trans-1,2- diaminocyclohexane-N,N,N',N'-tetraacetic acid (CyDTA) or its salt as a reaction stopper for a coupled reaction due to an isocitrate dehydrogenase. This method for measuring urea nitrogen adopts trans-1,2-diaminocyclohexane-N,N,N',N'- tetraacetic acid (CyDTA) or its salt as a reaction stopper for a coupled reaction due to an isocitrate dehydrogenase.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、試料中の尿素窒素
を測定する測定試薬及び測定方法に関するものであり、
イソクエン酸脱水素酵素(ICDH)による共役反応の
停止剤としてトランス−1,2−ジアミノシクロヘキサ
ン−N,N,N',N'−四酢酸(CyDTA)又はその
塩を使用するものである。本発明は、特に、化学、生命
科学、及び臨床検査等の分野において有用なものであ
る。本明細書においては、次の略語を使用することもあ
る。 α−KG :α−ケトグルタル酸 NADH :還元型ニコチンアミドアデニンジヌクレオチド NADPH :還元型ニコチンアミドアデニンジヌクレオチドリン酸 NAD(P)H:NADH又はNADPHを示す NAD(P)+ :NAD+又はNADP+を示す NAD+ :酸化型ニコチンアミドアデニンジヌクレオチド NADP+ :酸化型ニコチンアミドアデニンジヌクレオチドリン酸
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reagent and a method for measuring urea nitrogen in a sample.
Trans-1,2-diaminocyclohexane-N, N, N ', N'-tetraacetic acid (CyDTA) or a salt thereof is used as a terminator for a conjugation reaction by isocitrate dehydrogenase (ICDH). The invention is particularly useful in fields such as chemistry, life sciences, and clinical testing. The following abbreviations may be used herein. α-KG: α-ketoglutarate NADH: reduced nicotinamide adenine dinucleotide NADPH: reduced nicotinamide adenine dinucleotide phosphate NAD (P) H: indicates NADH or NADPH NAD (P) + : NAD + or NADP + NAD + : Oxidized nicotinamide adenine dinucleotide NADP + : Oxidized nicotinamide adenine dinucleotide phosphate

【0002】[0002]

【従来の技術】試料中の尿素窒素を測定する方法として
一般的に行われている方法は、尿素にウレアーゼを作用
させてアンモニアを生成させ、α−ケトグルタル酸とN
ADH又はNADPHの存在下でグルタミン酸脱水素酵
素(GLDH)によってNAD(P)HからNAD
(P)+への変化量を測定するというものである。
2. Description of the Related Art A commonly used method for measuring urea nitrogen in a sample is to react urease with urea to produce ammonia, and to produce α-ketoglutaric acid and N
Glutamate dehydrogenase (GLDH) converts NAD (P) H to NAD in the presence of ADH or NADPH.
(P) The amount of change to + is measured.

【0003】[0003]

【化1】 Embedded image

【0004】しかしながら、上記式(1)及び(2)に
示されるように、ウレアーゼ反応によりアンモニアを発
生させて尿素窒素を測定しようとするとき、試料中にあ
らかじめアンモニアが存在する場合には、このアンモニ
アが測定値に正誤差を与えるため、尿素窒素を正確に測
定することが出来なかった。そこで、以下の式(3)、
(4)及び(5)に示されるように、尿素にウレアーゼ
反応を行う前に、GLDH反応によって、試料中にあら
かじめ存在するアンモニアをグルタミン酸に分解して消
去する方法が一般的に行われてきた。
However, as shown in the above formulas (1) and (2), when ammonia is generated by the urease reaction to measure urea nitrogen, if ammonia is present in the sample beforehand, Urea nitrogen could not be measured accurately because ammonia gives a positive error to the measured values. Therefore, the following equation (3),
As shown in (4) and (5), a method has been generally employed in which, before performing a urease reaction with urea, ammonia previously present in a sample is decomposed into glutamic acid and eliminated by a GLDH reaction. .

【0005】[0005]

【化2】 Embedded image

【0006】しかし、この方法も、尿のようにアンモニ
アが高濃度に含まれる試料を測定する際には、このアン
モニアが測定値に正誤差を与える場合がある。このた
め、イソクエン酸脱水素酵素(ICDH)を、マグネシ
ウムイオンやマンガンイオン等の金属イオンの存在下で
作用させることにより、アンモニア消去時にNAD
(P)Hから変換されたNAD(P)+をNAD(P)
Hへ再生することで、アンモニアの消去能を増加させた
方法が行われている。この反応系は、次の式(6)、
(7)、(8)及び(9)で示される。
However, in this method, when measuring a sample containing a high concentration of ammonia such as urine, the ammonia sometimes gives a positive error to the measured value. Therefore, isocitrate dehydrogenase (ICDH) is allowed to act in the presence of a metal ion such as a magnesium ion or a manganese ion so that NAD can be eliminated when ammonia is eliminated.
(P) NAD (P) + converted from H is converted to NAD (P)
A method of increasing the erasing ability of ammonia by regenerating H has been performed. This reaction system has the following formula (6):
(7), (8) and (9).

【0007】[0007]

【化3】 Embedded image

【0008】式(6)及び(9)で示されるように、試
料中にあらかじめ存在するアンモニアの消去と尿素を分
解して得たアンモニアの測定は同じ共役反応によって行
われる。すなわち、尿素を分解して得たアンモニアを正
確に測定するためには、試料中のアンモニアの消去が完
了した後に、NAD(P)+をNAD(P)Hへ再生す
る反応を完了させ、NAD(P)Hの量を変換される前
の値にまで回復させた後、この再生反応を完全に停止さ
せることが必要となる。
As shown by the equations (6) and (9), the elimination of the ammonia present in the sample and the measurement of the ammonia obtained by decomposing the urea are performed by the same conjugate reaction. That is, in order to accurately measure the ammonia obtained by decomposing urea, after the elimination of ammonia in the sample is completed, the reaction of regenerating NAD (P) + into NAD (P) H is completed, and the NAD After restoring the amount of (P) H to the value before conversion, it is necessary to completely stop the regeneration reaction.

【0009】このICDHによる共役反応を停止させる
方法として、ICDHの反応に関与するマグネシウムイ
オンやマンガンイオン等の金属イオンを、金属キレート
剤を添加することによってマスキングする方法が広く知
られている。また、この金属キレート剤としては、一般
的にEDTAが使用されている。しかしながら、このE
DTAはマグネシウムイオンやマンガンイオン等の金属
イオンを完全にマスキングすることが出来ないため、I
CDHによる共役反応を完全に停止させるものではな
い。
As a method of stopping the conjugation reaction by ICDH, a method of masking a metal ion such as a magnesium ion or a manganese ion involved in the reaction of ICDH by adding a metal chelating agent is widely known. EDTA is generally used as the metal chelating agent. However, this E
DTA cannot completely mask metal ions such as magnesium ions and manganese ions.
It does not completely stop the conjugation reaction by CDH.

【0010】[0010]

【発明が解決しようとする課題】前記のように、ICD
Hによる共役反応を用いて、試料中の尿素窒素を測定す
る場合、試料中にあらかじめ存在するアンモニアの消去
と尿素を分解して得たアンモニアの測定が同じ共役反応
によって行われるため、尿素を分解して得たアンモニア
を正確に測定することが必要となる。このためには、I
CDHの反応に関与するマグネシウムイオンやマンガン
イオン等の金属イオンをマスキングすることにより、N
AD(P)Hから変換されたNAD(P)+をNAD
(P)Hへ再生する反応を完全に停止させることが必要
となる。すなわち、尿素を分解して得たアンモニアを正
確に測定するためには、試料中のアンモニアの消去が完
了した後に、NAD(P)+をNAD(P)Hへ再生す
る反応を完了させ、NAD(P)Hの量を変換される前
の値にまで回復させた後、この再生反応を完全に停止さ
せることが必要となる。本発明は、アンモニアによる測
定値への正誤差が生じるのを防ぎ、かつICDHによる
共役反応を完全に停止させることによって、試料中の尿
素窒素を正確に測定することが出来る測定試薬及び測定
方法の提供を目的とする。
As described above, the ICD
When urea nitrogen in a sample is measured using a conjugation reaction with H, the elimination of ammonia present in the sample and the measurement of ammonia obtained by decomposing urea are performed by the same conjugation reaction. It is necessary to accurately measure the ammonia obtained. For this, I
By masking metal ions such as magnesium ions and manganese ions involved in the reaction of CDH, N
NAD (P) + converted from AD (P) H is converted to NAD
(P) It is necessary to completely stop the reaction for regeneration to H. That is, in order to accurately measure the ammonia obtained by decomposing urea, after the elimination of ammonia in the sample is completed, the reaction of regenerating NAD (P) + into NAD (P) H is completed, and the NAD After restoring the amount of (P) H to the value before conversion, it is necessary to completely stop the regeneration reaction. The present invention relates to a measuring reagent and a measuring method capable of accurately measuring urea nitrogen in a sample by preventing the occurrence of a correct error in the measurement value due to ammonia and completely stopping the conjugation reaction by ICDH. For the purpose of providing.

【0011】[0011]

【課題を解決するための手段】本発明者らは、前記目的
を達成するために、鋭意検討を行った結果、イソクエン
酸脱水素酵素(ICDH)による共役反応の停止剤とし
てトランス−1,2−ジアミノシクロヘキサン−N,
N,N',N'−四酢酸(CyDTA)又はその塩を使用
することにより、ICDHによる共役反応を完全に停止
させることを確認して、本発明を完成するに至った。
Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above object, and as a result, trans-1,2 has been used as a terminator for a conjugation reaction by isocitrate dehydrogenase (ICDH). -Diaminocyclohexane-N,
By using N, N ', N'-tetraacetic acid (CyDTA) or a salt thereof, it was confirmed that the conjugation reaction by ICDH was completely stopped, and the present invention was completed.

【0012】従って、本発明は、ICDHによる共役反
応の停止剤としてCyDTA又はその塩を使用すること
を特徴とする尿素窒素の測定試薬及び測定方法である。
Accordingly, the present invention is a reagent and a method for measuring urea nitrogen, wherein CyDTA or a salt thereof is used as a terminator for a conjugation reaction by ICDH.

【0013】[0013]

【発明の実施の形態】本発明による尿素窒素の測定試薬
及び測定方法は、イソクエン酸脱水素酵素(ICDH)
による共役反応の停止剤としてトランス−1,2−ジア
ミノシクロヘキサン−N,N,N',N'−四酢酸(Cy
DTA)又はその塩を使用することを特徴とするもので
ある。すなわち、試料中にあらかじめ存在するアンモニ
アの消去が完了した後に、反応系にCyDTA又はその
塩を添加し、ICDHの反応に関与するマグネシウムイ
オンやマンガンイオン等の金属イオンを、CyDTA又
はその塩によってマスキングすることにより、NAD
(P)Hから変換されたNAD(P)+をNAD(P)
Hへ再生する反応を完全に停止させ、その後、試料中の
尿素窒素の正確な測定を行うものである。この反応系
は、次の式(10)、(11)、(12)、(13)及
び(14)で示される。
BEST MODE FOR CARRYING OUT THE INVENTION The reagent and method for measuring urea nitrogen according to the present invention comprise isocitrate dehydrogenase (ICDH).
Trans-1,2-diaminocyclohexane-N, N, N ', N'-tetraacetic acid (Cy
DTA) or a salt thereof. That is, after elimination of ammonia present in the sample is completed, CyDTA or a salt thereof is added to the reaction system, and metal ions such as magnesium ions and manganese ions involved in the reaction of ICDH are masked by CyDTA or a salt thereof. By doing, NAD
(P) NAD (P) + converted from H is converted to NAD (P)
The reaction to regenerate H is completely stopped, and thereafter, the accurate measurement of urea nitrogen in the sample is performed. This reaction system is represented by the following formulas (10), (11), (12), (13) and (14).

【0014】[0014]

【化4】 Embedded image

【0015】本発明における、CyDTAの塩として
は、例えば、ナトリウム、カリウム、若しくはリチウム
などのアルカリ金属との塩等を挙げることが出来る。
In the present invention, examples of the salt of CyDTA include a salt with an alkali metal such as sodium, potassium or lithium.

【0016】本発明における、ICDHの反応に関与す
る金属イオンとしては、例えば、マグネシウムイオン、
マンガンイオン、鉄イオン、銅イオン、亜鉛イオン、錫
イオン、カルシウムイオン等が挙げられる。
In the present invention, the metal ion involved in the reaction of ICDH includes, for example, magnesium ion,
Manganese ions, iron ions, copper ions, zinc ions, tin ions, calcium ions and the like can be mentioned.

【0017】また、反応系に対するCyDTA又はその
塩の添加量は、測定試薬又は測定反応系に含有される金
属イオンの濃度に対応させるものなので、一概にはいえ
ないものの、CyDTA又はその塩を金属イオンと等モ
ル濃度以上含有させるのが望ましい。好ましくは、金属
イオン濃度の10倍以上が望ましい。
Although the amount of CyDTA or its salt added to the reaction system corresponds to the concentration of the metal ion contained in the measuring reagent or the measuring reaction system, it cannot be said unconditionally. It is desirable to contain it in an equimolar concentration or more with ions. Preferably, the concentration is at least 10 times the metal ion concentration.

【0018】本発明において、試料中にあらかじめ存在
するアンモニアとは、内因性アンモニア、測定器具や測
定装置に付着しているアンモニア、或いは他の試薬から
混入したアンモニア等も含めるものとする。
In the present invention, the ammonia which is present in the sample in advance includes endogenous ammonia, ammonia adhering to a measuring instrument or a measuring device, or ammonia mixed from another reagent.

【0019】また、本発明において、試料としては、尿
素窒素を含むものであれば特に限定しない。例えば、ヒ
ト又は動物の血液、血清、血漿、髄液、尿等の体液;ヒ
ト若しくは動物の肝臓、腎臓等の臓器、毛髪等の抽出液
等が挙げられる。
In the present invention, the sample is not particularly limited as long as it contains urea nitrogen. Examples thereof include body fluids such as human or animal blood, serum, plasma, cerebrospinal fluid, and urine; and extracts of human or animal organs such as liver and kidney, hair and the like.

【0020】[0020]

【実施例】以下、実施例により本発明をより具体的に詳
述するが、本発明はこの実施例により限定されるもので
はない。 [実施例] (尿素窒素測定試薬におけるICDH反応停止効果の実
証)尿素窒素測定試薬にて、複数濃度のマグネシウムを
含有した試料中の尿素窒素濃度を測定して、ICDH反
応停止効果を確かめた。
EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. [Example] (Demonstration of ICDH reaction termination effect in urea nitrogen measurement reagent) The urea nitrogen concentration in a sample containing a plurality of concentrations of magnesium was measured with a urea nitrogen measurement reagent to confirm the ICDH reaction termination effect.

【0021】(1)試薬の調製 尿素窒素測定用第1試薬の調製 下記の試薬成分をそれぞれ記載の濃度になるように純水
に溶解し、pH7.2(20℃)に調整したものを調製
した。 測定試薬成分 濃 度 グッド緩衝液 30mM α−ケトグルタル酸 10mM イソクエン酸 10mM NADPH 0.32mM GLDH 5,000単位/L ICDH 1,000単位/L
(1) Preparation of Reagent Preparation of First Reagent for Urea Nitrogen Measurement The following reagent components were dissolved in pure water so as to have the respective concentrations described, and adjusted to pH 7.2 (20 ° C.). did. Measurement reagent components Concentration Good buffer 30 mM α-ketoglutarate 10 mM Isocitrate 10 mM NADPH 0.32 mM GLDH 5,000 units / L ICDH 1,000 units / L

【0022】本発明・尿素窒素測定用第2試薬の調製 下記の試薬成分をそれぞれ記載の濃度になるように純水
に溶解し、pH7.5(20℃)に調整したものを調製
した。 測定試薬成分 濃 度 グッド緩衝液 350mM α−ケトグルタル酸 10mM ウレアーゼ 8,100単位/L CyDTA 100mM
Preparation of Second Reagent for Measuring Urea Nitrogen of the Present Invention The following reagent components were dissolved in pure water so as to have the respective concentrations described below, and adjusted to pH 7.5 (20 ° C.). Measuring reagent components Concentration Good buffer 350 mM α-Ketoglutaric acid 10 mM Urease 8,100 units / L CyDTA 100 mM

【0023】対照・尿素窒素測定用第2試薬の調製 下記の試薬成分をそれぞれ記載の濃度になるように純水
に溶解し、pH7.5(20℃)に調整したものを調製
した。 測定試薬成分 濃 度 グッド緩衝液 350mM α−ケトグルタル酸 10mM ウレアーゼ 8,100単位/L EDTA 150mM
Preparation of Control / Preparation of Second Reagent for Urea Nitrogen Measurement The following reagent components were dissolved in pure water so as to have the concentrations described, respectively, and adjusted to pH 7.5 (20 ° C.). Measurement reagent components Concentration Good buffer 350 mM α-Ketoglutaric acid 10 mM Urease 8,100 units / L EDTA 150 mM

【0024】(3)尿素窒素の測定 日立製作所製7170形自動分析装置にて尿素窒素の測
定を行った。試料には、尿素窒素濃度500mg/dL
の水溶液にマグネシウムを各々41mM、82mM、1
23mM、165mM、206mMずつ添加した5種類
のものを用いた。この試料2μLに各々第1試薬として
尿素窒素測定用第1試薬を260μL加え37℃で5分
間反応させた後、第2試薬として尿素窒素測定用第2試
薬を65μL添加し混合液(最終反応液)とした。この
ときの最終反応液中のマグネシウム濃度は、各々0.2
5mM、0.50mM、0.75mM、1.01mM、
1.26mMであった。第2試薬添加後37℃で反応を
行わせ、主波長340nm及び副波長405nmにおけ
る第2試薬添加1分36秒目(22ポイント)と、第2
試薬添加3分20秒目(28ポイント)の吸光度の増加
分より、既知濃度の尿素窒素標準液を測定した時の吸光
度との比例計算によって尿素窒素濃度を求めた。
(3) Measurement of Urea Nitrogen Urea nitrogen was measured by a Hitachi 7170 type automatic analyzer. The sample contains a urea nitrogen concentration of 500 mg / dL.
Magnesium in the aqueous solution of 41 mM, 82 mM, 1
Five types were used, each of which was added at 23 mM, 165 mM, and 206 mM. After adding 260 μL of the first reagent for measuring urea nitrogen as the first reagent to each 2 μL of the sample and reacting at 37 ° C. for 5 minutes, 65 μL of the second reagent for measuring urea nitrogen was added as the second reagent, and the mixed solution (final reaction solution) was added. ). At this time, the magnesium concentration in the final reaction solution was 0.2
5 mM, 0.50 mM, 0.75 mM, 1.01 mM,
1.26 mM. After the addition of the second reagent, the reaction was allowed to proceed at 37 ° C.
From the increase in absorbance at 3 minutes and 20 seconds (28 points) at 3 minutes after the addition of the reagent, the urea nitrogen concentration was determined by proportional calculation with the absorbance when a urea nitrogen standard solution of known concentration was measured.

【0025】(4)測定結果 尿素窒素測定用第1試薬及び、本発明・尿素窒素測定用
第2試薬並びに対照・尿素窒素測定用第2試薬を用い
て、試料中の尿素窒素を測定した時の測定結果を図1に
示した。この図において、横軸は最終反応液中のマグネ
シウム濃度を表し、縦軸は本発明及び対照試薬による尿
素窒素濃度を表す。
(4) Measurement Results When urea nitrogen in a sample was measured using the first reagent for measuring urea nitrogen, the second reagent for measuring urea nitrogen and the second reagent for measuring urea nitrogen according to the present invention. FIG. 1 shows the measurement results. In this figure, the horizontal axis represents the magnesium concentration in the final reaction solution, and the vertical axis represents the urea nitrogen concentration according to the present invention and the control reagent.

【0026】[0026]

【図1】FIG.

【0027】この図より、対照試薬の場合は、最終反応
液中のマグネシウム濃度が0.50mMで尿素窒素濃度
に7%の負誤差を示し、マグネシウム濃度が増加する毎
に尿素窒素濃度の負誤差も増加していることが分かる。
これに対して、本発明測定試薬及び測定方法の場合は、
反応液中のマグネシウム濃度が1.26mMでも、尿素
窒素濃度にはほとんど誤差を生じていないことが分か
る。
From this figure, in the case of the control reagent, when the magnesium concentration in the final reaction solution was 0.50 mM, a negative error of 7% was shown in the urea nitrogen concentration. Is also increasing.
In contrast, in the case of the measurement reagent and the measurement method of the present invention,
It can be seen that even if the magnesium concentration in the reaction solution was 1.26 mM, there was almost no error in the urea nitrogen concentration.

【0028】このことより、本発明測定試薬及び測定方
法においては第1試薬中に添加したCyDTAが、マグ
ネシウムをマスキングすることによりICDHの活性を
完全に停止させ、正確な尿素窒素濃度を得られることが
確かめられた。
From the above, according to the measuring reagent and the measuring method of the present invention, CyDTA added to the first reagent completely stops the activity of ICDH by masking magnesium, thereby obtaining an accurate urea nitrogen concentration. Was confirmed.

【発明の効果】本発明の尿素窒素測定試薬及び測定方法
は、イソクエン酸脱水素酵素(ICDH)による共役反
応の停止剤としてトランス−1,2−ジアミノシクロヘ
キサン−N,N,N',N'−四酢酸(CyDTA)又は
その塩を使用することにより、EDTA等のキレート剤
では完全に停止させることが出来ないICDHによる共
役反応を完全に停止させることが出来るものである。従
って、本発明によれば、ICDHによる共役反応を用い
て、試料中の尿素窒素を測定する場合、反応系に添加し
たCyDTA又はその塩が、ICDHの反応に関与する
マグネシウムイオンやマンガンイオン等の金属イオンを
マスキングすることにより、NAD(P)Hから変換さ
れたNAD(P)+をNAD(P)Hへ再生する反応を
完全に停止させることが出来る。すなわち、試料中のア
ンモニアの消去が完了した後に、NAD(P)+をNA
D(P)Hへ再生する反応を完了させ、NAD(P)H
の量を変換される前の値にまで回復させた後、この再生
反応を完全に停止させることが出来る。このため、尿素
を分解して得たアンモニアを正確に測定することが出
来、試料中の尿素窒素の正確な測定を行うことが出来る
ものである。
Industrial Applicability The reagent and method for measuring urea nitrogen according to the present invention are used as a terminator for trans-1,2-diaminocyclohexane-N, N, N ', N' as a conjugation reaction by isocitrate dehydrogenase (ICDH). -By using tetraacetic acid (CyDTA) or a salt thereof, a conjugation reaction by ICDH, which cannot be completely stopped by a chelating agent such as EDTA, can be completely stopped. Therefore, according to the present invention, when urea nitrogen in a sample is measured using a conjugation reaction by ICDH, CyDTA or a salt thereof added to the reaction system contains magnesium ions and manganese ions involved in the reaction of ICDH. By masking the metal ions, the reaction of regenerating NAD (P) + converted from NAD (P) H to NAD (P) H can be completely stopped. That is, after the elimination of ammonia in the sample is completed, NAD (P) +
The reaction for regeneration to D (P) H is completed, and NAD (P) H
The regeneration reaction can be completely stopped after restoring the amount of to the value before conversion. Therefore, it is possible to accurately measure ammonia obtained by decomposing urea, and to accurately measure urea nitrogen in a sample.

【図面の簡単な説明】[Brief description of the drawings]

【図1】尿素窒素測定用第1試薬及び、本発明・尿素窒
素測定用第2試薬並びに対照・尿素窒素測定用第2試薬
を用いて、試料中の尿素窒素を測定した時の測定結果を
示す図面。
FIG. 1 shows the measurement results when urea nitrogen in a sample was measured using a first reagent for measuring urea nitrogen, a second reagent for measuring urea nitrogen and a second reagent for measuring urea nitrogen according to the present invention. Drawings shown.

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 イソクエン酸脱水素酵素による共役反応
の停止剤としてトランス−1,2−ジアミノシクロヘキ
サン−N,N,N',N'−四酢酸又はその塩を含有する
ことを特徴とする試料中の尿素窒素の測定試薬。
1. A sample containing trans-1,2-diaminocyclohexane-N, N, N ', N'-tetraacetic acid or a salt thereof as a terminator for a conjugation reaction by isocitrate dehydrogenase. For measuring urea nitrogen in water.
【請求項2】 イソクエン酸脱水素酵素による共役反応
の停止剤としてトランス−1,2−ジアミノシクロヘキ
サン−N,N,N',N'−四酢酸又はその塩を使用する
ことを特徴とする試料中の尿素窒素の測定方法。
2. A sample using trans-1,2-diaminocyclohexane-N, N, N ', N'-tetraacetic acid or a salt thereof as a terminator for a conjugation reaction by isocitrate dehydrogenase. For measuring urea nitrogen in air.
JP10374988A 1998-12-10 1998-12-10 Reagent for measuring urea nitrogen and measurement of urea nitrogen Withdrawn JP2000166596A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10374988A JP2000166596A (en) 1998-12-10 1998-12-10 Reagent for measuring urea nitrogen and measurement of urea nitrogen

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10374988A JP2000166596A (en) 1998-12-10 1998-12-10 Reagent for measuring urea nitrogen and measurement of urea nitrogen

Publications (1)

Publication Number Publication Date
JP2000166596A true JP2000166596A (en) 2000-06-20

Family

ID=18504773

Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
JP (1) JP2000166596A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7449305B2 (en) 2001-10-11 2008-11-11 Arkray, Inc. Method of pre-treating sample for measuring saccharified amine and method of measuring saccharified amine
USRE45074E1 (en) 2001-10-11 2014-08-12 Arkray, Inc. Method of pre-treating sample for measuring saccharified amine and method of measuring saccharified amine

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7449305B2 (en) 2001-10-11 2008-11-11 Arkray, Inc. Method of pre-treating sample for measuring saccharified amine and method of measuring saccharified amine
USRE43795E1 (en) 2001-10-11 2012-11-06 Arkray, Inc. Method of pre-treating sample for measuring saccharified amine and method of measuring saccharified amine
USRE45074E1 (en) 2001-10-11 2014-08-12 Arkray, Inc. Method of pre-treating sample for measuring saccharified amine and method of measuring saccharified amine
USRE45626E1 (en) 2001-10-11 2015-07-28 Arkray, Inc. Method of pre-treating sample for measuring saccharified amine and method of measuring saccharified amine
USRE46073E1 (en) 2001-10-11 2016-07-19 Arkray, Inc. Method of pre-treating sample for measuring saccharified amine and method of measuring saccharified amine

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