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Wako Diagnostics
• No hemoglobin interference up to 500 mg/dL
• Stable formulation, Long shelf life
• Highly precise, liquid reagent
• No interference from ascorbic acid levels up to 50 mg/dL
Serum bilirubin measurement is widely used as a screening test for
liver function. The methods most used for the determination of serum
bilirubin are the diazo coupling method and the bilirubin oxidase
enzymatic method. However, these methods have disadvantages such
as interference by coexistent serum substances and unsatisfactory
stability of reagents after preparation.
The Wako Direct Bilirubin V assay is based on a chemical oxidation
method which utilizes vanadate as an oxidizing agent. The Wako
Direct Bilirubin V assay shows good correlation with conventional
methods, no significant influence by coexistent serum substances,
and is a convenient ready-to-use liquid type reagent.
Catalog No. Product Name Pkg Size Storage
992-23691 Direct Bilirubin V Buffer 4 x 70 mL 2-10°C°
994-23891 Direct Bilirubin V Vanadate 4 x 18 mL 2-35°C
996-23591* Direct Bilirubin V Buffer 4 x 540 mL 2-10°C
998-23791* Direct Bilirubin V Vanadate 4 x 135 mL 2-35°C
993-73291 Bilirubin Calibrator 4 x 3mL 2-10°C
* Product size is available as a special purchase only.
Vanadate oxidation method
Direct BilirubinFor In Vitro Diagnostic Use
© Copyright 2012 Wako Life Sciences, Inc. Wako Life Sciences, Inc. 1025 Terra Bella Ave., Suite A Mountain View, CA 94043
E: [email protected] T: 650.210.9153 www.wakodiagnostics.com
WLS-1951C-M-1
Correlation:
Linearity:
0 1 2 3 4 50.0
0.5
1.0
1.5M
easu
rem
ents
(mg/
dL)
Intrafat (%)
Vanadate
Diazo
0 5 10 150
5
10
15
y = 1.003x + 0.09r = 0.997
Dire
ct B
iliru
bin
V (m
g/dL
)
Direct Bilirubin (Alkaline azobilirubin method) (mg/dL)
Interference Studies
No interference up to
Ascorbic Acid 50 mg/dL
Hemoglobin 500 mg/dL
Turbidity (intralipid) 5%
Further Performance CriteriaReagent stability: Unopened reagents are stable until expiration date when stored at 2 to 35°C. After opening the bottles, store at 2-10°C and use within one month.
0 2 4 6 8 100
10
20
30
40
Wak
o D
irect
Bili
rubi
n (m
g/dL
)
Dilution (/10)Di-tauro Bilirubin - saline
0 100 200 300 400 5000
1
2
3
4
5
Mea
sure
men
ts (m
g/dL
)
Hemoglobin (mg/dL)
Vanadate
Diazo
Performance characteristics
PrincipleWhen a sample is mixed with the reagent containing the vanadate, at pH 3, direct bilirubin in the sample is oxidized to biliverdin. This causes the absorbance of yellow, specific to bilirubin, to decrease. Therefore, the direct bilirubin concentration in the sample can be obtained by measuring the absorbances before and after the vanadate oxidation.
InstrumentsVarious automated analyzer applications are available.
For more product information, please contact customer service at 1-877-714-1924.
Vanadate Method versus Diazo Method
Linear Range: 0.1 - 20 mg/dL
AccuracyThe accuracy of this method is expressed by data comparison to other methods
Vanadate
Azobilirubin y = 1.329x - 0.059 r = 0.9970 Sy/x = 0.121 n = 44
Alkaline azobilirubin y = 0.905x - 0.045 r - 0.9989 Sy/x = 0.074 n = 44
Sample: human sera