This package insert follows the Pharmaceuticals, Medical devices and Other Therapeutic Products Act of Japan.
In Vitro Diagnostics
Marketing Approval No. 21600AMZ00593000** Revised: February 2021 (5th edition)* Revised: January 2017 (4th edition)

This package insert must be read carefully prior to use.
Urea nitrogen assay kit(Classification No.: 42849002)

values are seen in patients with heart disease, liver
disorder, dehydration, or hemorrhage (especiallygastrointestinal hemorrhage), as well as those withnephropathy.

QUALIGENT UN

Assay Principle
1. Assay Principle
First reaction:
Ammonia in the sample reacts with 2ketoisohexanoic acid and reduced nicotinamide
adenine dinucleotide (NADH) in the presence ofleucine dehydrogenase (LED). As a result,leucine and oxidized nicotinamide adenine
dinucleotide (NAD) are produced, and theabsorbance at 340 nm decreases.
Second reaction:
If urease is added after completion of the firstreaction, ammonia and carbonic acid areproduced from urea. Ammonia produced byurease reacts with 2-ketoisohexonic acid andreduced nicotinamide adenine dinucleotide in thepresence of leucine dehydrogenase. As a result,leucine and nicotinamide adenine dinucleotide
are produced, and the absorbance at 340 nm
decreases.
The concentration of urea nitrogen is determinedby subtracting the change of absorbance with thefirst reaction from the change with the second
reaction.

General Precautions ＊＊1. This product is for in vitro diagnostic use, andmust not be used for any other purposes.
2. Clinicians should make a comprehensive clinicaldecision based on assay results in conjunction
with clinical symptoms and other examination
results.
3. For the effects of an administered drug on themeasured value, carefully read the Precautions forUse in the package insert of the drug, especiallythe section about the effects on laboratory testresults. Please also read carefully the “2.
Interfering Substances,” in the “ProceduralPrecautions” section, as well as “2. Precautionsfor Assessment” in the “Assessment of Assay
Results” section, of this package insert.
4. This product should be used only as directed inthis package insert. Reliability of results cannot beguaranteed if there are any deviations from theinstructions in this package insert.
5. If the reagent accidentally comes in contact witheyes and/or mouth, rinse immediately with ample
water as first aid, and consult the doctor ifrequired.
6. Carefully read the operating instructions for eachtype of automated analyzers prior to using thisproduct. Parameters for each type of analyzers areavailable, and can be requested from SEKISUIMEDICAL CO., LTD. if required.
7. Perform a quality control test prior to assay toensure accuracy.

First reaction:
NH3 + 2-Ketoisohexanoic acid + NADHLED───▶ Leucine + H2O + NADSecond reaction: UreaseUrea + 2H2O ────▶ 2NH3＋H2CO3

Description (Kit Components) ＊Component: Ingredients
UN Enzyme Solution 1:
Nicotinamide adenine
dinucleotide (reduced form)
Sodium 2-ketoisohexanoate
Leucine dehydrogenase
UN Enzyme Solution 2:
Nicotinamide adenine
dinucleotide (reduced form)
Sodium 2-ketoisohexanoate
UreaseLeucine dehydrogenase

NH3 + 2-Ketoisohexanoic acid + NADH
LED────▶ Leucine + H2O + NAD

2. Features
1) The influence of endogenous ammonia can beavoided.
2) Analytical results are hardly affected byhemolysis or bilirubin.
＊＊Procedural Precautions ＊1. Properties of Samples and Sampling Methods
1) Samples
Serum, plasma (heparin plasma, EDTA
plasma and citrated plasma) and urine may
be used.
When urine is measured, dilute it 1:21 withphysiological saline in advance or measure it
by using separately designated parameters.
2) Storage of samples2)
If the isolated serum or plasma sample
cannot be tested on the same day, specimens

Intended Use
Measurement of urea nitrogen in serum, plasmaor urine
Urea is the final product of protein metabolism. It isreleased into the blood from the liver and theneliminated from the body via the kidneys. In patientswith nephropathy, the blood urea nitrogen level
increases because of impaired excretion. Abnormal

1should be stored as follows:
2–10C: for tests within 1 week≤ -20C: for tests after more than 1 week
Bring samples to room temperature (15–30C) before use.
Urine samples should be tested on the sameday.
2. Interfering substances
Assay results are not affected by free bilirubin(up to 20 mg/dL), conjugated bilirubin (up to 20mg/dL), hemoglobin (up to 500 mg/dL), ascorbic
acid (up to 50 mg/dL), formazin turbidity (up to3000 FTU), or ammonia (up to 80 mg/dL).
3. Others
1) Always use Serum Multicalibrator (SEKISUI),
Seronorm Multicalibrator, Seronorm Human orAnaserum UN standard solution for calibration.
2) Precautions for assay range
If the concentration of sample exceeds assay
range, dilute the sample with saline and repeat
the measurement.

nitrogen.
2. Accuracy: 90–110% of the expected assay value
3. Within-run Reproducibility:
Coefficient of variation ≤ 5%(Test methods used for 1. –3. are in-housemethods.)
4. Measurement Range4): (On a Hitachi 9000 series
automated analyzer)
0.6–300 mg/dL
5. Correlation4)
1) Serum N=63 r=0.999 y=0.99x–0.08
Control method: Approved in vitro diagnostic(urease-GLDH method)
2) Plasma N=88 r=0.999 y=0.98x –0.29
Control method: Approved in vitro diagnostic(urease-GLDH method)3) Urine
N=50 r=0.999 y=0.98x –2.06
Control method: Approved in vitro diagnostic(urease-GLDH method)
6. Standard Material
SRM912 (NIST)
Precautions for Use or Handling ＊1. Precautions for Handling (to Ensure Safety)
1) All samples used in the test should be handled
as a material possibly infected with HIV, HBV,HCV, or other viruses. To prevent infection, use
disposable gloves and avoid mouth pipetting
during the test.
2) Sodium azide is added as an antiseptic agent in
the UN Enzyme Solution 1 and UN Enzyme
Solution 2. Therefore, if the reagent comes in
accidentally contact with eyes, mouth or skin,rinse immediately with ample water as first aid,and consult the doctor if required.
2. Precautions for use
1) This product should be stored as directed,
without freezing. Freezing can deteriorate thereagents, which can produce inaccurate results.
Therefore, avoid using the reagents which havebeen previously frozen.
2) Do not use expired reagents. Use of suchreagents cannot guarantee the reliability ofmeasurement values.
3) Do not perform the assay under direct sunlight
3. Precautions for Disposal
1) Before disposal, used samples and theircontainers must be immersed in sodium
hypochlorite solution at a concentration ofgreater than 0.1% for longer than 1 hour orautoclaved at 121ºC for 20 minutes.
2）To prevent infections from spilled samples orsolutions containing samples, wipe the spilledarea thoroughly with disinfectants such as
sodium hypochlorite solution at a concentrationof greater than 0.1%.
3) The reagents and treated samples should bediscarded as medical waste or industrial waste
according to the waste disposal regulations.
4) The reagents should be disposed of inaccordance with the Water Pollution Control
act or related regulations.
5) Sodium azide has been added as anantisepticagent in the UN Enzyme Solution 1and UN Enzyme Solution 2. It can react withlead or copper pipes to produce the highly＊＊

Dosage/Administration (Assay Procedure) ＊1. Preparation of reagents
Reagent (1): UN Enzyme Solution 1 is ready to use.
Reagent (2): UN Enzyme Solution 2 is ready to use.
2. Assay Procedure
This product is compatible with Hitachi 9000
series and LABOSPECT series automatedanalyzers. Assay procedure is indicated below.
37CSample Reagent (1)Measurement+────▶
(absorbance I※)
5.0 μL100 μL
59–293 sec
37CReagent (2) ────▶ Measurement(absorbance II※)
33 μL
65–299 sec
Calculation of────▶
concentration※

Absorbances I and II: The difference inabsorbance between 700 nm and 340 nm.
Calibration material: Serum Multicalibrator(SEKISUI), Seronorm Multicalibrator, Seronorm
Human or Anaserum UN standard solution(Manufacture's assigned value)
Reagent blank: Purified water or saline＊＊Assessment of Assay Results ＊1. Reference standard range3)
In blood: 8–20 mg/dL3) (Equivalent to urea of 17- 43 mg/dL)(Within the JCCLS common standard)
2. Precautions for Assessment
There may be reactions or interfering reactions
with non-target substances. If assay resultsappear to be unreliable, repeat the measurement(if necessary, after dilution) or try anotheranalytical methods.
＊＊

Performance ＊1. Sensitivity
1) Reagent blank: change in absorbance being
equal to or lower than 0.010/min
2) Sensitivity: The change of absorbance is0.035–0.065/min per 50 mg/dL of urea

2

explosive metal azide. Therefore, the reagent
should be flushed with large amounts of water
during disposal.
4. Other precautions
1) Do not use the containers for other purposes.
2) Do not take apart the reagent cartridge before.
Storage and Shelf Life ＊1. Storage temperature: 2–10C
2. Shelf life: 1 year from the date of manufacture(The expiration date is printed on the outer package.)
Packaging＊Name

QUALIGENT
UNPackage
UN Enzyme
Solution 1Set
(Cassette for 1 × 15.0 mL
Hitachi
UN Enzyme
9000 series)
Solution 2
1 × 5.0 mL
UN Enzyme
L set
Solution 1(Set for1 × 46 mL
Hitachi
UN Enzyme
LABOSPE
Solution 2CT series)
1 × 16 mL×2×2＊＊References ＊1) Morishita Y. et al.: J Jpn Soc Clin Chem 25,Enlarged No. 3, 30c, 1996. Japanese.
2) Sasaki M1. et al.: Sampling of constituents of
the human body, Tokyo: Kodansha; 1972.
Japanese.
3) Kanai M. (supervising editor): Kanai’s manualof clinical laboratory medicine. 35th ed. Tokyo:Kanehara Shuppan; 2020. Japanese.
4) SEKISUI MEDICAL CO., LTD. In house data.
Japanese.
Contact
SEKISUI MEDICAL CO., LTD.
international@sekisui.com

Manufacturer ＊SEKISUI MEDICAL CO., LTD.
1-3, Nihonbashi 2-chome, Chuo-ku, Tokyo, Japan"QUALIGENT" and "Anaserum" are trademarks orregistered trademarks of SEKISUI MEDICAL CO.,LTD. in Japan and/or other countries.
All other brands, product names and service names
are trademarks or registered trademarks of theirrespective companies.

3