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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: diagnostics@wakousa.com 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