SIGMA DIAGNOSTICS CREATININE REAGENT KIT

K963534 · Sigma Diagnostics, Inc. · CGX · Sep 30, 1996 · Clinical Chemistry

Device Facts

• Record ID: K963534
• Device Name: SIGMA DIAGNOSTICS CREATININE REAGENT KIT
• Applicant: Sigma Diagnostics, Inc.
• Product Code: CGX · Clinical Chemistry
• Decision Date: Sep 30, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1225
• Device Class: Class 2

Intended Use

The Sigma Diagnostics Creatinine Reagent Set for the SYNCHRON CX®3 is formulated based on a modification of the Jaffe reagents described by Heinegard and Tiderstrom. These modifications minimize the effect of interfering substances. Both creatinine reagents are used to measure creatinines concentrations in serum, plasma, or urine on the SYNCHRON CX®3 System.

Device Story

Reagent set for quantitative creatinine measurement; utilizes modified Jaffe reaction (alkaline picrate) to produce colorimetric signal; processed on SYNCHRON CX®3 System; used in clinical laboratory settings by trained personnel; output provides creatinine concentration values; aids clinicians in assessing renal function and detecting renal disease.

Clinical Evidence

Bench testing only. Comparison studies against predicate using serum and urine samples. Serum correlation coefficient 0.999 (y=1.03x-0.01); urine correlation coefficient 0.998 (y=0.99x+0.21). Precision: serum %CV <4.5%, urine %CV <2.1%. Linearity: serum up to 25 mg/dL, urine 10-400 mg/dL.

Technological Characteristics

Colorimetric reagent set based on modified Jaffe reaction (alkaline picrate). Designed for use on SYNCHRON CX®3 automated analyzer. Measures creatinine concentration via spectrophotometric detection of yellow/orange color formation.

Indications for Use

Indicated for the quantitative measurement of creatinine in human serum, plasma, or urine to assist in the detection of renal disease and estimation of renal function impairment.

Regulatory Classification

Identification

A creatinine test system is a device intended to measure creatinine levels in plasma and urine. Creatinine measurements are used in the diagnosis and treatment of renal diseases, in monitoring renal dialysis, and as a calculation basis for measuring other urine analytes.

Predicate Devices

• Beckman Creatinine Reagent Kit (Part No. 443340)

Submission Summary (Full Text)

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K963534 SEP 30 1996

510(K) NOTIFICATION

Sigma Diagnostics

545 South Ewing Avenue

St. Louis, MO 63103

CX®3 Creatinine Reagent Set

Procedure Number C7058

August 31, 1996

# SUMMARY OF SAFETY AND EFFECTIVENESS

Creatinine is synthesized in the kidney, the liver, and the pancreas.¹ It is transported in the blood to other organs such as muscle and brain where it is phosphorylated to phosphocreatine. Some free creatine in muscle is converted to creatinine daily, and the amount of creatinine produced is proportional to muscle mass. In the absence of renal disease, the excretion rate of creatinine in an individual is relatively constant. Therefore, measurement of creatinine clearance is useful in detecting renal disease and estimating the extent of impairment of renal function.²

Most methods for creatinine measurement are based on the Jaffe reaction, where yellow/orange color forms when the metabolite is treated with alkaline picrate.³ The Sigma Diagnostics Creatinine Reagent Set for the SYNCHRON CX®3 is formulated based on a modification of the Jaffe reagents described by Heinegard and Tiderstrom. These modifications minimize the effect of interfering substances.⁴

The safety and effectiveness of Sigma Diagnostics Creatinine Reagent Set, Procedure Number C7058, is demonstrated by its substantial equivalency to Beckman Creatinine Reagent Kit, Part No. 443340. Both creatinine reagents are used to measure creatinines concentrations in serum, plasma, or urine on the SYNCHRON CX®3 System, and the reaction principles for both reagents are identical. In comparison studies, a correlation coefficient of 0.999 and a regression equation of $y = 1.03x - 0.01$ was obtained with serum samples; and a correlation coefficient of 0.998 and a regression equation of $y = 0.99x + 0.21$ was obtained with urine samples. With-in run precision and total precision demonstrated %CV’s of less than 4.5 % on serum samples and less than 2.1 % on urine samples. The Sigma Diagnostics Creatinine Reagent has been determined to be linear to 25 mg/dL with serum samples, and from 10 to 400 mg/dL with urine samples on the SYNCHRON CX®3 System.

# REFERENCES:

1. Tietz NW: Textbook of clinical chemistry. WB Saunders, Philadelphia, 1986, pp 1271 - 1281.
2. Bowers LD, Wong ET: Kinetic serum creatinine assays. Ill. An initial evaluation and review. Clin Chem 26:555, 1980
3. Jaffe M: Ueber den Niederschlag, welchen Picrinsaure in narmalen Harm eraeugt und über eine neue Reaction des Kreatinins. Hoppe Seylers Z Physiol Chem 10:391, 1886
4. Tietz, NW, Clinical Guide to Laboratory Tests, WB Saunders, Co, Philadelphia, 1983