SIGMA DIAGNOSTICS BUN REAGENT

K963537 · Sigma Diagnostics, Inc. · LFP · Oct 24, 1996 · Clinical Chemistry

Device Facts

• Record ID: K963537
• Device Name: SIGMA DIAGNOSTICS BUN REAGENT
• Applicant: Sigma Diagnostics, Inc.
• Product Code: LFP · Clinical Chemistry
• Decision Date: Oct 24, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1770
• Device Class: Class 2

Intended Use

The Sigma Diagnostics BUN Reagent is formulated to use this methodology on the SYNCHRON CX®3 System.

Device Story

Reagent kit for quantitative BUN measurement; used on SYNCHRON CX®3 System. Principle: urease-based enzymatic reaction; measures rate of increase in conductivity resulting from ammonium bicarbonate production. Used in clinical laboratory settings by trained personnel. Output: BUN concentration (mg/dL). Clinical utility: screening for kidney function impairment (e.g., nephritis, glomerulonephritis, tubular necrosis) and monitoring liver disease status. Results assist clinicians in diagnosing renal and hepatic conditions.

Clinical Evidence

Bench testing only. Comparison study using serum samples yielded correlation coefficient of 0.999 and regression equation y = 1.03x - 0.19. Precision testing (within-run and total) showed %CV < 4%. Linearity established up to 125 mg/dL.

Technological Characteristics

Enzymatic reagent (urease) for conductivity-based detection. Designed for use on SYNCHRON CX®3 automated clinical chemistry analyzer. Linear range up to 125 mg/dL.

Indications for Use

Indicated for the quantitative determination of blood urea nitrogen (BUN) in human serum or plasma as a screening procedure for evaluating kidney function.

Regulatory Classification

Identification

A urea nitrogen test system is a device intended to measure urea nitrogen (an end-product of nitrogen metabolism) in whole blood, serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of certain renal and metabolic diseases.

Predicate Devices

• Beckman BUN Reagent Kit, Part No. 443350

Submission Summary (Full Text)

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OCT 24 996
K963537
Sigma Diagnostics
545 South Ewing Avenue
St. Louis, MO 63103
CX®3 BUN Reagent
Procedure Number B1657
August 31, 1996

# SUMMARY OF SAFETY AND EFFECTIVENESS

The level of blood urea nitrogen (BUN) is regulated by the metabolism of proteins and by the renal excretion of urea.¹ BUN determination, therefore, has become the most widely used screening procedure for evaluating kidney function. Increased BUN levels occur in cases of impaired kidney function such as chronic nephritis, acute glomerulonephritis, polycystic disease of the kidney, nephrosclerosis and tubular necrosis.² BUN levels are also elevated due to urinary tract obstruction and during the terminal stage of liver disease. Decrease in BUN levels often accompany primary hepatic insufficiency and acute hepatitis.

In 1961, Chin and Kroontje reported a method for determining urea based upon the difference in conductivity of urea and the ammonium bicarbonate produced by urease form urea.³ In 1971, the method was modified to detect urea by measuring the rate of increase of conductivity.⁴ The Sigma Diagnostics BUN Reagent is formulated to use this methodology on the SYNCHRON CX®3 System.

The safety and effectiveness of Sigma Diagnostics BUN Reagent, Procedure Number B1657, are demonstrated by its substantial equivalency to Beckman BUN Reagent Kit, Part No. 443350. Both reagents are used to measure BUN concentrations in serum or plasma on the SYNCHRON CX®3 System, and the reaction principles for both are identical. In a comparison study, a correlation coefficient of 0.999 and a regression equation of y = 1.03x - 0.19 was obtained with serum samples. With-in run precision and total precision on serum samples demonstrated %CV’s of less than 4%. The Sigma Diagnostics BUN Reagent has been determined to be linear to 125 mg/dL.

## REFERENCES

1. Cantarow A, Trumper M: Clinical Biochemistry, WB Saunders Company, Philadelphia, 1975, pp 207-209
2. Tietz NW: Fundamentals of Clinical Chemistry, WB Saunders Company, Philadelphia, 1976, p 993
3. Textbook of Clinical Chemistry, NW Tietz, Editor, WB Saunders Company, Philadelphia, 1986
4. Chin WT, Kroontje W: Anal Chem 33:1757, 1961