This package insert follows the Pharmaceuticals, Medical devices and Other Therapeutic Products Act of Japan.
In Vitro Diagnostics
Marketing Approval No. 21600AMZ00488000** Revised: April 2021 (7th edition)* Revised: May 2020 (6th edition)

This package insert must be read carefully prior to use.
Creatinine assay kit(Classification No.: 30161002)

Assay Principle ＊＊1. Assay Principle
In the first reaction, creatine in samples isdegraded into water and oxygen by the action ofcreatinase, sarcosine oxidase, and catalase.
In the second reaction, creatinine in samples isconverted to creatine by the action of creatininase
and then sarcosine is produced by the action ofcreatinase. In the presence of hydrogen peroxide
produced by sarcosine oxidase and peroxidase(POD), oxidative condensation of N-ethyl-Nsulfobutyl-m-toluidine (ESBmT) and 4aminoantipyrine is allowed to occur. The
concentration of creatinine is determined bymeasuring the absorbance of the resulting quinone
dye (red-purple).

QUALIGENT CRE
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 withclinical symptoms and other examination results.
3. For the effects of an administered drug on themeasured value, carefully read the Precautions for
Use in the package insert of the drug, especiallythe section about the effects on laboratory test
results. Please also read carefully the “2.
Interfering Substances,” in the “ProceduralPrecautions” section, as well as “2. Precautions forAssessment” in the “Assessment of Assay Results”
section, of this package insert.
4. This product should be used only as directed in thispackage 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:

Creatinase

Creatine + H2O

Sarcosine +Urea

Sarcosine oxidase
Sarcosine + O2 + H2O
Glycine + HCHO +H2O2Catalase
2H2O2
H2O＋O2
Second reaction:
Creatinine + H2OCreatininase

Creatine

Creatinase

Creatine + H2O

Sarcosine +Urea
Sarcosine oxidase
Sarcosine + O2 + H2O
Glycine + HCHO +
H2O2

POD

H2O2+ESBmT+4-Aminoantipyrine
Quinonedye (red-purple)
2. Features
1) Liquid reagents, ready-to-use.
2)The enzymatic method is employed．

Description (Kit Components) ＊Component: Ingredients
CRE Enzyme Solution 1: Creatinase
Sarcosine oxidase
N-Ethyl-N-sulfobutyl-mtoluidine disodium salt
CRE Enzyme Solution 2: Creatininase
4-Aminoantipyrine＊＊

Procedural Precautions ＊1. Properties of Samples and Sampling Methods
1) Samples
Serum, plasma, or urine (primitive or diluted
1:21) may be used.
2) Storage of samples1)
If the isolated serum or plasma sample cannot
be tested on the same day, specimens should
be stored as follows:
2–10C: for tests within 1 week

Intended Use
Measurement of creatinine in serum, plasma, orurine
Creatinine is a degradation product of high-energy
creatine phosphate that is released into the bloodfrom the muscles and nerves. Creatinine is filtered by
the renal glomeruli and is excreted in the urine,
mostly without reabsorption.
Because the blood level of creatinine is increased inpatients with renal failure, uremia, and heart failure,
it plays an important role as an index of kidney
function in the diagnosis and evaluation of these
diseases.

≤ -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
1) Assay results are not affected by free bilirubin(up to 20 mg/dL), conjugated bilirubin (up to1

20 mg/dL), hemoglobin (up to 300 mg/dL),ascorbic acid (50 mg/dL), or formazinturbidity (up to 3000 FTU).
2) Turbid samples such as chyle samples may
give positive errors to analytical results.
3) In high immunoglobulin samples, turbidity
may be produced after adding the first reagent,and negative errors may be given to analyticalresults.
4) Sodium azide that is added as a preservative
for samples may give positive errors toanalytical results.
3. Others
1) Always use Serum Multicalibrator (SEKISUI),
Seronorm Multicalibrator or Anaserum CRE
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.

2) Sensitivity: The absorbance is 0.15–0.27 per 10
mg/dL of creatinine.
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 Range10): (On a Hitachi 9000 series
automated analyzer)
0.1–230 mg/dL
5. Correlatio10)
1) Serum N=75 r=0.999 y=1.03x -0.03
Control method: Approved in vitro diagnostic(enzymatic method)
2) Plasma N=50 r=0.999 y=0.98x-0.01
Control method: Approved in vitro diagnostic(enzymatic method)3) Urine (primitive urine)
N=55 r=0.999 y=0.97 x+1.82
Reference method: Approved in vitro diagnostic(Enzymatic method: urine diluted 1:21)
6. Standard Material
SRM914 (NIST)＊＊

Dosage/Administration (Assay Procedure) ＊1. Preparation of reagents
Reagent (1): CRE Enzyme Solution 1 is ready touse.
Reagent (2): CRE Enzyme Solution 2 is ready touse.
2. Assay Procedure
This product is compatible with Hitachi 9000
series and LABOSPECT series automatedanalyzers. Assay procedure is indicated below.
37CSample Reagent (1)+2.5 μL
100 μL
5 min
Reagent (2)+ 50 μL

37C
5 min

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) Proclin 300, which possesses skin-irritative
potential, is added as an antiseptic agent in theCRE Enzyme Solution 2. Therefore, if thereagent comes in contact with skin or clothes,rinse immediately with ample water, and consult
the doctor if skin irritation develops.
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 replenish the reagents.
4) 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 or
autoclaved 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.
4. Other precautions

Measurement(Absorbance I※)
Measurement(Absorbance II※)
Calculation ofconcentration※Absorbance I and II: The difference in absorbance
between 700 nm and 546 nm
Calibration material: Serum Multicalibrator(SEKISUI), Seronorm Multicalibrator orAnaserum CRE Standard Solution (Manufacture'sassigned value)
Reagent blank: Purified water or saline

Assessment of Assay Results ＊＊1. Reference standard range2)
Serum: Male, 0.65–1.07 mg/dL
Female, 0.46–0.79 mg/dL
Urine: 0.5–1.5 g/day
2. Precautions for Assessment
There may be reactions or interfering reactions
with non-target substances. If assay results appear
to be unreliable, repeat the measurement (ifnecessary, after dilution) or try another analyticalmethods.
Performance
1. Sensitivity
1) Reagent blank: absorbance being equal to orlower than 0.05

21) Do not use the containers for other purposes.
2) Do not take apart the reagent cartridge beforeuse.
Storage and Shelf Life
1. Storage temperature: 2–10C
2. Shelf life: 13 months from the date of manufacture(The expiration date is printed on the outer
package.)
Packaging ＊NameSet(Cassette for
Hitachi 9000series)
QUALIGENT CRE

L set(Set forHitachi
LABOSPECT series)

Package
CRE Enzyme
Solution 1
1 × 15.0 mL
CRE Enzyme
Solution 2
1 × 7.5 mL
CRE Enzyme
Solution 1
1 ×40 mL
CRE Enzyme
Solution 2
1 × 20 mL×2×2

References ＊＊1) Sasaki M. et al.: Sampling of constituents of thehuman body, Tokyo: Kodansha; 1972. Japanese.
2) Kanai M. (supervising editor): Kanai’s manual ofclinical laboratory medicine. 35th ed. Tokyo:Kanehara Shuppan; 2015. Japanese.
3) Yoshimura M. et al.: Jpn J Clin Med (extraedition), 53, 464, 1995. Japanese.
4) Osawa S.: Med Tech, 26, 389, 1998. Japanese.
5) Nakahara M. et al.: Jpn J Med Tech, 45, 1106,1996. Japanese.
6) Sasaki T: Mod Med Lab, 15, 259, 1987.
7) Suzuki M., Yoshida M.: Clin. Chim. Acta, 143,147, 1984.
8) Yasuhara M et al.: Mod Med Lab, 18, 31, 1990.
Japanese.
9) Japan Society of Clinical Chemistry: Jpn J Clin
Chem, 23, 326, 1994. Japanese..
10) 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.

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