DIAZYME SODIUM ENZYMATIC ASSAY

K042189 · Diazyme Laboratories · MZU · Oct 7, 2004 · Clinical Chemistry

Device Facts

• Record ID: K042189
• Device Name: DIAZYME SODIUM ENZYMATIC ASSAY
• Applicant: Diazyme Laboratories
• Product Code: MZU · Clinical Chemistry
• Decision Date: Oct 7, 2004
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1665
• Device Class: Class 2

Intended Use

Diazyme Sodium Enzymatic Assay Kit in conjunction with Diazyme Sodium Low and High Calibrators, are intended for the quantitative determination of sodium (NA) in serum. Diazyme Sodium Enzymatic Assay Kit contains a low level standard and a high level standard. The standards are used to generate a linear graph that will be used in the calculation of sodium concentrations in unknown serum samples. Diazyme Sodium Enzymatic Assay has controls for normal serum sodium level and abnormal serum sodium level. The controls are used as reference samples for checking the functionality of the Diazyme Sodium Enzymatic Assay.

Device Story

Spectrophotometric assay for quantitative determination of sodium in human serum; utilizes sodium-dependent beta-galactosidase activity with ONPG substrate. Reagent 1 mixed with serum, incubated at 37°C for 5 minutes; Reagent 2 added; absorbance measured at 405 nm at 3 and 5 minutes. Output is absorbance value proportional to sodium concentration, used to calculate sodium levels via linear graph generated by bi-level calibrators. Used in clinical laboratory settings by trained personnel. Results assist healthcare providers in assessing patient sodium status. Benefits include enzymatic alternative to ion-selective electrode methods.

Clinical Evidence

No clinical studies performed. Evidence consists of analytical bench testing: precision/reproducibility (CV 0.98-1.54%), linearity (117-200 mmol/L, R²=0.9915), and method comparison against predicate (n=66, Y=0.9736X+4.3832, R²=0.9965). Interference testing showed <10% deviation for common serum substances.

Technological Characteristics

Two-reagent (R1 and R2) kinetic enzymatic assay. Principle: Sodium-dependent beta-galactosidase activity. Detection: Spectrophotometric absorbance at 405 nm. Measuring range: 80-180 mmol/L. Form factor: Liquid reagents for automated clinical analyzers. No software algorithm or connectivity specified; operates as a chemical reagent system.

Indications for Use

Indicated for the quantitative determination of sodium in human serum for clinical monitoring of sodium levels.

Regulatory Classification

Identification

A sodium test system is a device intended to measure sodium in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of aldosteronism (excessive secretion of the hormone aldosterone), diabetes insipidus (chronic excretion of large amounts of dilute urine, accompanied by extreme thirst), adrenal hypertension, Addison's disease (caused by destruction of the adrenal glands), dehydration, inappropriate antidiuretic hormone secretion, or other diseases involving electrolyte imbalance.

Predicate Devices

• Synchron LX I 725 Clinical System (K023049)

Submission Summary (Full Text)

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K042189

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OCT 7 - 2004

# Summary

Submitter's name:

Diazyme Laboratories Division, General Atomics

Submitter's address:

Phone: Fax:

Name of Contact Person:

3550 General Atomics Court San Diego, CA 92121 858-455-4761 858-455-4750

Huan Tran Diazyme Laboratories Division General Atomics 3550 General Atomics Court San Diego, CA 92121 Phone: [phone] Fax: [phone]

Date the summary was prepared:

August 6, 2004

| Name of the device: | Sodium Enzymatic Assay |
|----------------------|---------------------------------|
| Trade Name: | Diazyme Sodium Enzymatic Assay |
| Common/Usual Name: | Enzymatic Assay, Sodium |
| Classification Name: | Electrode, Ion Specific, Sodium |
| Device Class: | II |

### Predicate Device:

The legally marketed device to which we are claiming equivalence [807.92(a)(3)]: Synchron LX I 725 Clinical System (K023049) manufactured by Beckman Coulter Inc., Brea, CA, USA.

#### Description of the devices

In healthy individual, an extracellular fluid level of sodium is regulated to maintain at 135-145mM. Small deviations from normal level can have severe health consequences. Monitoring serum sodium concentration is important in both routine check and emergency rooms. Currently, the two most commonly used methods to detect serum sodium are ion-selective electrode (ISE) and flame photometry. However, routine maintenance of these analyzers requires much effort and sometimes would be cumbersome. Diazyme's Sodium Enzymatic assay is proven to be equivalent to ISE method but more user friendly in automated analyzers.

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Sodium is determined enzymatically via sodium dependent ß-galactosidase activity with ONPG as substrate. The absorbance at 405 nm of the product O-nitrophenyl is proportional to the sodium concentration.

Nat → o-nitrophenol + galactose ONPG ß-galactosidase

ONPG = o-nitropheny1 -ß-D-galactopyranose

### Intended Use of the Device:

Diazyme Sodium Enzymatic Assay Kit in conjunction with Diazyme Sodium Low and High Calibrators, are intended for the quantitative determination of sodium (NA) in serum.

#### Performance Characteristics

Diazyme's Sodium Enzymatic Assay is a two reagent (R1 and R2) based kinetic assay system. The results are obtained in 10 min by measuring absorbance at 405 nm. No off line pretreatment is needed. The assay has a wide measuring range from 80 to 180 mmol/L of serum sodium. The assay offers excellent precision as shown in the table below:

| | 144mM Na+ | 164mM Na+ |
|------------------|-----------|-----------|
| Within Precision | CV%=3.2% | CV%=3.0% |
| Total Precision | CV%=5.3% | CV%=3.3% |

Diazyme's Sodium Enzymatic assay has a good correlation with ISE method with a correlation coefficient of 0.96. The average analytical recoveries for sodium added to two different sera were 104% and 97% respectively. We have conducted interference study by spiking the substances to be tested to the pooled human sera and found little interference at the indicated concentrations:

| Interference | Concentration |
|---------------|---------------|
| NH4Cl | 1 mM |
| NaPi | 1.5 mM |
| CaCl2 | 5 mM |
| NaCl | 200 mM |
| CuCl2 | 0.25 mM |
| ZnCl2 | 0.25 mM |
| FeCl3 | 0.025 mM |
| Ascorbic Acid | 5 mM |
| Glucose | 5 mM |
| Bilirubin | 10mg/dl |

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#### Conclusion:

Comparison analysis presented in the 510K submission for this device in the comparison section, together with linearity, precision and interference study presented demonstrated that the Diazyme's Sodium Enzymatic Assay has excellent accuracy and is safe and effective. There is no significant deviation between the results obtained by Diazyme's Sodium Enzymatic Assay and legally marketed predicate when testing clinical patient serum samples Therefore, Diazyme's Sodium Enzymatic Assay is substantially similar to the commercially available products to measure sodium levels in human serum samples.

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/3/Picture/1 description: The image shows the logo for the Department of Health & Human Services. The logo is a circle with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" around the perimeter. Inside the circle is an image of an eagle with its wings spread. The eagle is facing to the right and has three lines representing its wings.

Public Health Service

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

OCT 7 - 2004

Mr. Huan Tran Quality Assurance Manager Diazyme Laboratories 3550 General Atomics Court San Diego, CA 92121

k042189 Re: Trade/Device Name: Diazyme Sodium Enzymatic Assay Kit Regulation Number: 21 CFR 862.1665 Regulation Name: Sodium test system Regulatory Class: Class II Product Code: MZU, JIT, JJX Dated: August 9, 2004 Received: August 12, 2004

Dear Mr. Tran:

We have reviewed your Section 510(k) premarket notification of intent to market the device we have teviewed your becamed the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate for use stated in the encrosale) to regars actment date of the Medical Device Amendments, or to conninered prior to May 20, 2017, in accordance with the provisions of the Federal Food, Drug, de vices that have been recuire approval of a premarket approval application (PMA). and Cosmetter recry. tee, the device, subject to the general controls provisions of the Act. The r ou may, therefore, mains of the Act include requirements for annual registration, listing of general controls profitering practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it your device to such additional controls. Existing major regulations affecting your device it may be subject to back of Federal Regulations (CFR), Parts 800 to 895. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean I hat FDA has made a determination that your device complies with other requirements of the Act that I Dr Has Intacted and regulations administered by other Federal agencies. You must or any I with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820).

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This letter will allow you to begin marketing your device as described in your Section 510(k) I his icter will anow you to ough finding of substantial equivalence of your device to a legally premaince houricated device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific information about the application of labeling requirements to your device, If you destions on the promotion and advertising of your device, please contact the Office of of questions on the promote and Safety at [phone]. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). You may obtain other general information on your responsibilities under the Act from the I ou may oount one. Echerers, International and Consumer Assistance at its toll-free number [phone] or [phone] or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html.

Sincerely yours,

Sean M. Cooper US, DVM.

Jean M. Cooper, MS, D.V.M. Director Division of Chemistry and Toxicology Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

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## Indications for Use

510(k) Number (if known): K042189

Device Name: Diazyme Sodium Enzymatic Assay Kit

Indications for Use:

Diazyme Sodium Enzymatic Assay Kit in conjunction with Diazyme Sodium Low Diazyme Coularn LEE are intended for the quantitative determination of sodium (NA) in serum.

Diazyme Sodium Enzymatic Assay Kit contains a low level standard and a high level standards The standards are used to generate a linear graph that will be iever bland and ulation of sodium concentrations in unknown serum samples.

Diazyme Sodium Enzymatic Assay has controls for normal serum sodium level and abnormal serum sodium level. The controls are used as reference samples for checking the functionality of the Diazyme Sodium Enzymatic Assay.

Prescription Use (Part 21 CFR 801 Subpart D) AND/OR

Over-The-Counter Use (21 CFR 807 Subpart C)

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of In Vitro Diagnostic Devices (OIVD)

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Office of In Vitro Diagnostic
Device Evaluation and Safety

510(k) K042189