WAKO DIRECT BILIRUBIN V

K970986 · Wako Chemicals USA, Inc. · CIG · May 7, 1997 · Clinical Chemistry

Device Facts

• Record ID: K970986
• Device Name: WAKO DIRECT BILIRUBIN V
• Applicant: Wako Chemicals USA, Inc.
• Product Code: CIG · Clinical Chemistry
• Decision Date: May 7, 1997
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1110
• Device Class: Class 2

Intended Use

Wako Total Bilirubin V is based on a chemical oxidation method, utilizing vanadate as an oxidizing agent, shows good correlation with conventional methods, practically no interference by coexistent serum substances, and is convenient ready-to-use liquid type reagent.

Device Story

In vitro diagnostic reagent for serum direct bilirubin measurement; utilizes vanadate oxidation method. Sample mixed with reagent containing detergent and vanadate at pH 3; direct bilirubin oxidized to biliverdin; absorbance decrease measured at specific wavelength. Used in clinical laboratory settings by trained personnel. Output is direct bilirubin concentration (mg/dL). Assists clinicians in assessing liver function and diagnosing hepatobiliary disorders.

Clinical Evidence

Bench testing only. Comparison study against predicate assay (n=unspecified) yielded correlation coefficient 0.997, regression y=1.003x + 0.09. Precision studies confirmed day-to-day reproducibility. Analytical sensitivity (LOD) 0.03 mg/dL; linearity range 0-20 mg/dL.

Technological Characteristics

Liquid reagent containing detergent and vanadate. Chemical oxidation principle (vanadate-based). Photometric measurement of absorbance change at pH 3. Standalone diagnostic assay.

Indications for Use

Indicated for the quantitative determination of direct bilirubin in human serum as a screening test for liver function.

Regulatory Classification

Identification

A bilirubin (total or direct) test system is a device intended to measure the levels of bilirubin (total or direct) in plasma or serum. Measurements of the levels of bilirubin, an organic compound formed during the normal and abnormal distruction of red blood cells, if used in the diagnosis and treatment of liver, hemolytic hematological, and metabolic disorders, including hepatitis and gall bladder block.

Predicate Devices

• Direct Bilirubin assay (K912024/A)

Submission Summary (Full Text)

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WAKO

Wako Chemicals USA, Inc.

1600 Bellwood Road, Richmond, VA 23237 U.S.A.

Telephone [phone] Telex 293208 WAKO UR(RCA) Facsimile [phone]

K970986

MAY - 7 1997

# 510(k) Summary of Safety and Effectiveness

Serum bilirubin measurement is widely used as a screening test for liver functions. The methods most widely used for determination of serum bilirubin are the diazo coupling method $^{1)2)3)}$ and the bilirubin oxidase enzymatic method $^{4)}$. However, these methods have disadvantages such as interference by coexistent serum substances unsatisfactory stability of reagents after preparation. Wako Total Bilirubin V is based on a chemical oxidation method, utilizing vanadate as an oxidizing agent, shows good correlation with conventional methods, practically no interference by coexistent serum substances, and is convenient ready-to-use liquid type reagent $^{5)}$.

When a sample is mixed with the reagent containing the detergent and the vanadate, at around 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 absorbance before and after the vanadate oxidation.

The safety and effectiveness of the Wako Direct Bilirubin V assay is demonstrated by its substantial equivalency to our previous Direct Bilirubin assay (510(k)#K912024/A). Both test systems are used to measure total bilirubin is serum. In comparison studies against the predicate assay, a correlation coefficient of 0.997 and a regression equation $y=1.003x + 0.09$ was obtained with serum samples. Precision studies indicate acceptable values can be obtained on a day to day basis. The minimum detectable level of this method is $0.03 \, \text{mg/dL}$. The Wako Direct Bilirubin V assay is linear to $20 \, \text{mg/dL}$.

# References

1. Malloy H.T., Evelyn K.L. The determination of bilirubin with the photoelectric colorimetry. J.Biol.Chem., 199: 481-490, (1937).
2. Jendrassik L., Cleghorn R.A. Photometrische bilirubinbestimmung. Biochem.Z., 289: 1-14, (1937).
3. Michaelsson M. Bilirubin determination in serum and urine. Scand. J.Clin.Lab.Invest.,12(Suppl 56): 1-80, (1937).
4. Murao S., Tanaka N. A new enzyme "bilirubin oxidase" produced by Myrothecium varrucaria MT-1. Agric.Biol.Chem. 45: 2383-2384, (1981).
5. Tokuda K. and Tanimoto K. New method of measuring serum bilirubin using vanadic acid. Jpn.Clin.Chem., 22(2), 116-122 (1993).

LaTonya Mallory

Wako Chemicals USA, Inc.

April 30, 1997