BIOLABO

www.biolabo.f
UREA Colorimetric
r
MANUFACTURER:
Method
BIOLABO SAS, Reagent for quantitative determination
of urea in human serum and
Les Hautes Rives
plasma or urines.
02160, Maizy,
France REF 80221 R1 1 x 125 mL R2 1 x 1.25 mL R3 1 x 31 mL R4 1 x 10 mL

IVD
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TECHNICAL SUPPORT AND ORDERS
Tel: (33) 03 23 25 15 50
Made In France
support@biolabo.fr
Latest revision: www.biolabo.fr I: corresponds to significant
modifications

I INTENDED USE SAFETY CAUTION

This reagent is designated for professional use in  Refer to current Material Safety Data Sheet available on
laboratory (semi- automated or automated method). request or on www.biolabo.fr
It allows quantitative determination of of urea in human  Verify the integrity of the contents before use.
serum and  Waste disposal: Respect legislation in force in the country.
plasma or urines to screen its level.  All specimens or reagents of biological origin should be
GENERALITIES (1) (5) handled as potentially infectious. Respect legislation in
force in the country.
More than 90% of urea is excreted through the kidneys in
urines. Measurement of the plasma or serum urea Any serious incident that has occurred in connection with the
concentration is widely regarded as a test of renal function. device is notified to the manufacturer and the competent
However, a number of nonrenal factors also influence the authority of the Member State in which the user and/or
circulating urea concentration: Urea increased level occurs patient
REAGENTSis based.
PREPARATION
when proteins catabolism is accelerated, burns, stress,
myocardial infarction... Urea is decreased in acute liver Working reagent: Add contents of vial R2 into vial R1
destruction and is accompanied with increased ammonium (Salicylate). Mix gently by inversion.
level. Urea level is generally studied in conjunction with Base (vial R3): Dilute (1 + 3) with demineralised
creatinine level (urea/creatinine ratio) to refine post-renal or water In some cases (automated procedure),
pre-renal
PRINCIPLE diagnosis.
(4) may be used pur
Enzymatic and colorimetric method based on the specific Standard (vial R4): ready for use.
action of urease which hydrolyses urea in ammonium ions STABILITY AND STORAGE
and carbon dioxide. Ammonium ions then form with chloride Stored away from light, well caped in the original vial at 2-8°C,
and salicylate a blue-green complex. This coloration, and used as described, reagents are stable:
proportional to urea concentration in the specimen, is Unopened:
measured at 600 nm. Until expiry date stated on the label of
REAGENTS the kit Once opened, without
R1 UREA Salicylat -
contamination:
Working reagent (R1 + R2) is stable 1 month.
Salicylate e
31 mmol/L - Base (vial R3) dilutd ¼ is stable 1 month.
Nitroprussia 1.67 - Standard (vial R4): Transfer the requested quantity,
te mmol/L
Warning: Eye Irrit. 2: H319 – causes serious eye recap, and store at 2-8°C
irritation P280: wear protective gloves/eye  Discard any reagent if cloudy or if if blank at 600 nm
protection/face protection > 0.100.
P305+P351+P338: IF IN EYES, Rinse cautiously with water several Don’t use reagents after expiry date.
minutes; Remove contact lenses, if present and easy to do. SPECIMEN COLLECTION AND HANDLING (2)
Continue rinsing.
Unhemolysed serum or heparinised plasma. Avoid fluoride or
Classification due to sodium salicylate 1 - <2.5%. For more details, refer
R2 UREA Urease ammonium as anticoagulant which interfere with the assay.
to safety data sheet (SDS).
Urease > 15 Urea is stable in serum or plasma for:
 24 h at room temperature.
KUI/L
Working reagent (R1+R2) is not classified as  several days at 2-8°C.
dangerous.  at least 2-3 months frozen.
Sodium 7 24h Urine: diluted (1+19) with demineralised water
R3 UREA Base
hypochlorite mmol/L before assay. Urea is stable in urines for:4 days at 2-8°C.
Sodium
Before hydroxide
dilution: 62– may be corrosive to
Danger: Met. Corr. 1: H290 Add antibacterial agent as Thymol to improve the
mmol/L
metals Skin CORR. 1B ; H314 – causes severe skin burnsand eye stability.
damage.
P280: wear protective gloves/eye protection/face protection
LIMITS (3)
P305+P351+P338: IF IN EYES, Rinse cautiously with water several For a more comprehensive review of factors affecting this
minutes; Remove contact lenses, if present and easy to do. assay refer to the publication of Young D.S.
Continue rinsing.
Classification due to sodium hydroxide, sodium hypochlorite 1 - <2.5%. I MATERIAL REQUIRED BUT NOT PROVIDED
For more details, refer to safety data sheet (SDS). 1. Basic medical analysis laboratory equipment.
Once diluted, reagent is not classified as dangerous according to
2. Spectrophotometer or Biochemistry Clinical
regulation
Analyzer
1272/2008/EC.

R4 UREA Standard Urea 40 mg/dL (6.66

mmol/L)
Reagents R2 and R4 are not classified as dangerous according to
regulation 1272/2008/EC.
UR4_220E_IFU_80221_V03_202307
11
CALIBRATION (4) PROCEDURE
 REF 95015 Multicalibrator traceable to SRM
Manual procedure
 With 909c.
manual procedure only: Standard Let stand reagents and specimens at room
(vial aR4)
Make new calibration when changing reagent batch, if temperature.
quality control results are found out of the established range Pipette into test tubes Blank Standard Assay
and after maintenance operations.
Working reagent (R1+R2) 1 mL 1 mL 1 mL
The calibration frequency depends on proper instrument
functions and on the preservation of reagents. Demineralised water 5 µL
Standard 5 µL
QUALITY CONTROL
Specimen (Note 1) 5 µL
 REF 95010: Exatrol N
Level 1 Mix and wait for 4 minutes at room temperature or 2 minutes
at 37°C
 External
REF 95011: Exatrol
quality P program.
control Base (vial R3) diluted ¼ 1 mL 1 mL 1 mL
It Level 2
is recommended to control in the following cases:
 At least once a run Mix. Let stands for 8 minutes at room temperature or 5
 At least once within 24 hours minutes at 37°C. Read absorbance at 600 nm (590-610)
against blank (Note 3). Reaction coloration is stable for 2
 When changing vial of reagent
1- Performances with manual procedure should be validated
hours.
After maintenance operations on the
by user. 2- For better sensitivity, specimen volume may be
instrument If control is out of range, apply
enhanced to
following actions: 10 µL, with lowest linearity at 600 nm
1. Prepare a fresh control serum and repeat
3 Sensitivity is higher at upper wavelength and lower at
the test
inferior wavelength
2. If control is still out of range, use a new
vial of fresh calibrator 4 On Kenza Max at 578 nm, specimen volume is 10 µL to
optimize the couple sensitivity/linearity
3.If control is still out of range, use a new vial of reagent and
re-assay If control is still (2)
out of range, please contact 5 Above linearity limit dilute specimen with saline solution
REFERENCE INTERVAL
BIOLABO technical support or your local Agent.[mmol/L] and re- assay considering dilution factor.
In serum and plasma mg/dL 6 Specific applications for automatic analyzers are
In cord 45-86 [7.5-14.3] available on request.
Premature 6-54 [1.1-8.9] CALCULATION
< 1 year 9-41 [1.4-6.8] Manual procedure:
Children 11-39 [1.8-6.4] Serum and plasma:
18-60 years 13-43 [2.1-7.1] Abs (Assay)
Result = x
60-90 years 17-49 [2.9-8.2]
Standard concentration Abs
> 90 years 21-66 [3.6-11.1] (Standard)
In urines 26-43 g/24 h [0.43-0.71 mol/24 h] Urines diluted (1+19): Multiply the result by 20
Each laboratory should establish its own normal ranges for (dilution factor).
the population that it serves. To calculate blood urea nitrogen (BUN): multiply the value
Automatic
of Biochemistry
urea (mg/dL) analyzer:
by 0.467.
PERFORMANCES The analyzer provides directly calculated result.
On Cobas Mira, 37°C, 600
nm For more details about calibration and calculation of results,
Reproducibilit refer to
Repeatability:
Within run Level1 Level2 Level3 y: run Level1
Between Level2 Level3 User’s manual and specific application
N = 20 N = 20
REFERENCES
Mean mg/dL 25 59 141 Mean mg/dL 14 47 153 (1) TIETZ N.W. Textbook of clinical chemistry, 3rd Ed. C.A. Burtis, E.R.
S.D. mg/dL 0,5 0,78 1,27 S.D. mg/dL 0,77 1,55 3,52 Ashwood, W.B. Saunders (1999) p. 1239-1241.
(2) Clinical Guide to Laboratory Test, 4th Ed., N.W. TIETZ (2006) p. 1096-
C.V. % 2.0% 1.3% 0.9% C.V. % 5.5% 3.3% 2.3% 1099.
(3) YOUNG D.S., Effect of Drugs on Clinical laboratory Tests, 4th Ed. (1990)
Manual procedure: p. 3-599 to 3-609
(4) SEARCY R.L., REARDON J.E., FOREMAN J.A., Amer. J. Méd. Techn.
Measuring range: up to 250 mg/dL (41.7
1967, 33, 15-20.
mmol/L) Detection limit: approximately 10 (5) Bernard S. Bioch. clin. Diagnostics médicaux chirurgicaux 2ème éd. p.143-
144. Ed. Maloine PARIS (1989).
mg/dL.
(4) SRM: Standard Reference Material ®
Analytical sensitivity (1 cm): approx. 0.400 abs. (100
mg/dL) Comparison with commercially available
reagent:
y Total bilirubin
= 0.9816 + 0.87 No
r=interference
0.9961 up to 583µmol/L
Ascorbic acid No interference up to 2500 mg/dL
Interferences:
Glucose No interference up to 1110 mg/dL
Turbidity No interference of the turbidity up to 0.333
abs.
Haemoglobin No interference up to 248 µmol/L
Other substances may interfere (see §
Limits)

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H2O

Manufacturer Expiry date In vitro diagnostic Storage temperature Dematerialized
water Dilute with

REF
UR4_220E_IFU_80221_V03_202307
LOT
11
Product Reference See Insert Batch number Store away from light Sufficient for