ACE CARBON DIOXIDE REAGENT, ACE DIRECT BILIUBIN REAGENT, ACE TOTAL BILIRUBIN REAGENT, ACE MAGNESIUM REAGENT
Device Facts
| Record ID | K123953 |
|---|---|
| Device Name | ACE CARBON DIOXIDE REAGENT, ACE DIRECT BILIUBIN REAGENT, ACE TOTAL BILIRUBIN REAGENT, ACE MAGNESIUM REAGENT |
| Applicant | Alfa Wassermann Diagnostic Technologies, Inc. |
| Product Code | KHS · Clinical Chemistry |
| Decision Date | May 2, 2013 |
| Decision | SESE |
| Submission Type | Traditional |
| Regulation | 21 CFR 862.1160 |
| Device Class | Class 2 |
Indications for Use
The ACE Carbon Dioxide (CO2-LC) Reagent is intended for the quantitative determination of carbon dioxide concentration in serum and lithium heparin plasma using the ACE, ACE Alera, and ACE Axcel Clinical Chemistry Systems. Bicarbonate/carbon dioxide measurements are used in the diagnosis and treatment of numerous potentially serious disorders associated with changes in body acid-base balance. This test is intended for use in clinical laboratories and physician office laboratories. For in vitro diagnostic use only. The ACE Direct Bilirubin Reagent is intended for the quantitative determination of direct bilirubin concentration in serum and lithium heparin plasma using the ACE, ACE Alera, and ACE Axcel Clinical Chemistry Systems. Measurements of the levels of bilirubin, an organic compound formed during the normal and abnormal destruction of red blood cells, is used in the diagnosis and treatment of liver, hemolytic, hematological and metabolic disorders, including hepatitis and gall bladder block. This test is intended for use in clinical laboratories and physician office laboratories. For in vitro diagnostic use only. The ACE Total Bilirubin Reagent is intended for the quantitative determination of total bilirubin concentration in serum and lithium heparin plasma using the ACE, ACE Alera and ACE Axcel Clinical Chemistry System. Measurements of the levels of bilirubin, an organic compound formed during the normal and abnormal destruction of red blood cells is used in the diagnosis and treatment of liver, hemolytic, hematological and metabolic disorders, including hepatitis and gall bladder block. This test is intended for use in clinical laboratories and physician office laboratories. For in vitro diagnostic use only. The ACE Magnesium Reagent is intended for the quantitative determination of magnesium in serum and lithium heparin plasma using the ACE, ACE Alera and ACE Axcel Clinical Chemistry Systems. Magnesium measurements are used in the diagnosis and treatment of hypomagnesemia (abnormally low plasma levels of magnesium) and hypermagnesemia (abnormally high plasma levels of magnesium). This test is intended for use in clinical laboratories and physician office laboratories. For in vitro diagnostic use only.
Device Story
Reagents for quantitative photometric analysis of CO2, direct bilirubin, total bilirubin, and magnesium; used on ACE, ACE Alera, and ACE Axcel Clinical Chemistry Systems. Input: serum or lithium heparin plasma samples. Operation: CO2 uses coupled enzymatic reaction (PEPC/MD) measuring absorbance decrease at 408 nm; Bilirubin assays use diazotized sulfanilic acid forming azobilirubin measured at 554 nm; Magnesium uses xylidyl blue-1 in alkaline medium forming red complex. Output: quantitative concentration values. Used in clinical labs/POLs by trained operators. Results assist clinicians in diagnosing acid-base imbalances, liver/metabolic disorders, and magnesium level abnormalities.
Clinical Evidence
Bench testing only. Precision studies (within-run and total) performed on ACE, ACE Alera, and ACE Axcel systems across multiple concentrations. Matrix comparison studies (serum vs. plasma) showed high correlation (r > 0.98) and slope near 1.0. Linearity and interference studies confirmed performance within specified ranges. Point-of-care (POL) precision and method comparison studies at 3 sites confirmed comparability to in-house results.
Technological Characteristics
Photometric clinical chemistry reagents. CO2: enzymatic (PEPC/MD). Bilirubin: diazo method. Magnesium: xylidyl blue-1 colorimetric. Form factor: liquid ready-to-use or kit-based reagents. Analyzers: ACE, ACE Alera, ACE Axcel. Traceability: NIST SRM 351 (CO2), 916 (Total Bili), 909 (Mg).
Indications for Use
Indicated for quantitative determination of CO2, direct bilirubin, total bilirubin, and magnesium in serum and lithium heparin plasma. Used for diagnosis/treatment of acid-base balance disorders, liver, hemolytic, hematological, metabolic disorders (hepatitis, gall bladder block), hypomagnesemia, and hypermagnesemia. Intended for clinical and physician office laboratories.
Regulatory Classification
Identification
A bicarbonate/carbon dioxide test system is a device intended to measure bicarbonate/carbon dioxide in plasma, serum, and whole blood. Bicarbonate/carbon dioxide measurements are used in the diagnosis and treatment of numerous potentially serious disorders associated with changes in body acid-base balance.
Predicate Devices
- Alfa Wassermann ACE Carbon Dioxide (CO2-LC) Reagent, ACE Direct Bilirubin Reagent, ACE Total Bilirubin Reagent, and ACE Magnesium Reagent (k931786)
Submission Summary (Full Text)
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1
# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY ONLY TEMPLATE
A. 510(k) Number:
k123953
B. Purpose for Submission:
New reagents (Carbon Dioxide, Direct Bilirubin, Total Bilirubin, and Magnesium) added onto ACE Alera instrument (k123018)
Addition of lithium heparin plasma samples to already cleared reagents (CO2, T.Bilirubin, D.Bilirubin, and Mg on the ACE (k931786) and ACE Axcel (k113435) instruments).
C. Measurand:
Carbon Dioxide, Direct Bilirubin, Total Bilirubin, and Magnesium
D. Type of Test:
Quantitative, photometric methods
E. Applicant:
Alfa Wassermann Diagnostic Technologies, Inc.
F. Proprietary and Established Names:
ACE Carbon Dioxide (CO2-LC) Reagent
ACE Direct Bilirubin Reagent
ACE Total Bilirubin Reagent
ACE Magnesium Reagent
G. Regulatory Information:
1. Regulation section:
| Product Code | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| KHS | II | 862.1160, Bicarbonate/Carbon-Dioxide test system | 75-Chemistry |
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| CIG | II | 862.1110, Bilirubin (total or direct) test system | 75-Chemistry |
| --- | --- | --- | --- |
| JGJ | II | 862.1495, Magnesium test system | 75-Chemistry |
## H. Intended Use:
1. Intended use(s):
See indications for use below.
2. Indication(s) for use:
**ACE Carbon Dioxide (CO2-LC) Reagent**
The ACE Carbon Dioxide (CO2-LC) Reagent is intended for the quantitative determination of carbon dioxide concentration in serum and lithium heparin plasma using the ACE, ACE Alera, and ACE Axcel Clinical Chemistry Systems. Bicarbonate/carbon dioxide measurements are used in the diagnosis and treatment of numerous potentially serious disorders associated with changes in body acid-base balance. This test is intended for use in clinical laboratories or physician office laboratories. For in vitro diagnostic use only.
**ACE Direct Bilirubin Reagent**
The ACE Direct Bilirubin Reagent is intended for the quantitative determination of direct bilirubin concentration in serum and lithium heparin plasma using the ACE, ACE Alera, and ACE Axcel Clinical Chemistry Systems. Measurements of the levels of bilirubin, an organic compound formed during the normal and abnormal destruction of red blood cells, is used in the diagnosis and treatment of liver, hemolytic, hematological and metabolic disorders, including hepatitis and gall bladder block. This test is intended for use in clinical laboratories or physician office laboratories. For in vitro diagnostic use only
**ACE Total Bilirubin Reagent**
The ACE Total Bilirubin Reagent is intended for the quantitative determination of total bilirubin concentration in serum and lithium heparin plasma using the ACE, ACE Alera and ACE Axcel Clinical Chemistry System. Measurements of the levels of bilirubin, an organic compound formed during the normal and abnormal destruction of red blood cells, is used in the diagnosis and treatment of liver, hemolytic, hematological and metabolic disorders, including hepatitis and gall bladder block. This test is intended for use in clinical laboratories or physician office laboratories. For in vitro diagnostic use only.
**ACE Magnesium Reagent
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The ACE Magnesium Reagent is intended for the quantitative determination of magnesium in serum and lithium heparin plasma using the ACE, ACE Alera and ACE Axcel Clinical Chemistry Systems. Magnesium measurements are used in the diagnosis and treatment of hypomagnesemia (abnormally low plasma levels of magnesium) and hypermagnesemia (abnormally high plasma levels of magnesium). This test is intended for use in clinical laboratories or physician office laboratories. For in vitro diagnostic use only.
3. Special conditions for use statement(s):
For prescription and point-of-care use.
4. Special instrument requirements:
ACE Clinical Chemistry System
ACE Alera Clinical Chemistry System
ACE Axcel Clinical Chemistry System
I. Device Description:
The ACE Carbon Dioxide Reagent comes in a kit containing 4 x 7.5 mL Carbon Dioxide Reagent and 1 x 15 mL 30 mEq/L Carbon Dioxide Standard. The kit supports 500 tests.
The ingredients of the reagents are:
Carbon Dioxide Reagent
Phosphoenolpyruvate (PEP) 63 mmol/L
Nicotinamide adenine dinucleotide (NADH) analog, reduced 3.0 mmol/L
Phosphoenol pyruvate carboxylase (PEPC) (Microbial) >2000 U/L
Malate dehydrogenase (MD) (Mammalian) >20 KU/L
Buffer (pH 7.5 @ 25°C)
Activators, Stabilizers, Surfactant and Preservative
Carbon Dioxide Standard
Sodium carbonate 30 mEq/L, Buffer and Preservative
The ACE Direct Bilirubin Reagent comes in a kit containing 3x12 mL Direct Bilirubin Reagent and 3x3mL Sodium Nitrite Reagent. Each kit supports 120 tests.
The ingredients of the reagents are:
Direct Bilirubin Reagent
Sulfanilic acid 35.6 mmol/L
Hydrochloric acid 165 mmol/L
Sodium Nitrite Reagent
Sodium nitrite 43.5 mmol/L
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The ACE Total Bilirubin Reagent comes in a kit containing 3x30 mL Total Bilirubin Reagent and 3x6mL Sodium Nitrite Reagent. Each kit supports 300 tests.
The ingredients of the reagents are:
- Total Bilirubin Reagent
- Sulfanilic acid 35.6 mmol/L
- Hydrochloric acid 165 mmol/L
- Dimethyl sulfoxide (DMSO) 50% (v/v)
**Sodium Nitrite Reagent**
Sodium nitrite 60.0 mmol/L
The ACE Magnesium Reagent comes in a kit containing 6x12 mL liquid ready-to-use bottles. Each kit supports 160 tests.
ACE Magnesium Reagent has the following composition:
- Xylidyl blue-1 0.14 mmol/L
- EGTA 0.1 mmol/L
- Buffer and Surfactant
**J. Substantial Equivalence Information:**
1. Predicate device name(s):
- ACE Carbon Dioxide (CO₂-LC) Reagent
- ACE Direct Bilirubin Reagent
- ACE Total Bilirubin Reagent
- ACE Magnesium Reagent
2. Predicate 510(k) number(s):
- k931786
3. Comparison with predicate:
**Device Comparison Table: ACE Carbon Dioxide (CO₂-LC) Reagent**
| Similarities and Differences | | |
| --- | --- | --- |
| Item | Candidate Device | Predicate Device (ACE CO₂) |
| Intended Use | For the quantitative determination of carbon dioxide concentration in human serum. | Same |
| Instrument Platform | ACE, ACE Alera, and ACE Axcel analyzers | ACE analyzer |
| Sample Type | Serum and lithium heparin plasma | Serum |
| Expected value | 23-29 mEq/L | Same |
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| Similarities and Differences | | |
| --- | --- | --- |
| Item | Candidate Device | Predicate Device (ACE CO2) |
| Measuring range | 4 - 50 mEq/L | Same |
Device Comparison Table: ACE Direct Bilirubin Reagent
| Similarities and Differences | | |
| --- | --- | --- |
| Item | Candidate device | Predicate device (ACE Direct Bilirubin) |
| Intended Use | For the quantitative determination of direct bilirubin concentration in human serum. | Same |
| Instrument Platform | ACE, ACE Alera, and ACE Axcel analyzers | ACE analyzer |
| Sample Type | Serum and lithium heparin plasma | Serum |
| Expected value | <0.2 mg/dL | Same |
| Measuring range | 4 – 50 mg/dL | Same |
Device Comparison Table: ACE Total Bilirubin Reagent
| Similarities and Differences | | |
| --- | --- | --- |
| Item | Candidate device | Predicate device (ACE Total Bilirubin) |
| Intended Use | The ACE For the quantitative determination of total bilirubin concentration in human serum. | Same |
| Instrument Platform | ACE, ACE Alera and ACE Axcel analyzers | ACE analyzer |
| Sample Type | Serum and lithium heparin plasma | Serum |
| Expected value | 0.2-1.0 mg/dL | Same |
| Measuring range | 0.2 – 40 mg/dL | Same |
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Device Comparison Table: ACE Magnesium Reagent
| Similarities and Differences | | |
| --- | --- | --- |
| Item | Candidate device | Predicate device (ACE Magnesium) |
| Intended Use | For the quantitative determination of magnesium in human serum. | Same |
| Instrument Platform | ACE, ACE Alera and ACE Axcel analyzers | ACE analyzer |
| Sample Type | Serum and lithium heparin plasma | Serum |
| Expected value | 1.6-2.6 mg/dL | Same |
| Measuring range | 0.4 – 6.1 mg/dL | Same |
K. Standard/Guidance Document Referenced (if applicable):
CLSI Guideline EP05-A2: Evaluation of Precision Performance of Quantitative Measurement Methods
CLSI Guideline EP06-A: Evaluation of the Linearity of Qualitative Measurement Methods
CLSI Guideline EP07-A2: Interference Testing in Clinical Chemistry
CLSI Guideline EP09-A2: Method Comparison and Bias Estimation Using Patient Samples
CLSI Guideline EP10-A3: Preliminary Evaluation of Quantitative Clinical Laboratory Measurement Procedures
CLSI Guideline EP17-A: Protocols for Determination of Limits of Detection and Limits of Quantitation
L. Test Principle:
ACE Carbon Dioxide (CO2-LC) test:
The ACE Carbon Dioxide (CO2-LC-LC) test is based on a photometric test using a
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coupled enzymatic reaction (phosphoenol-pyruvate carboxylase and malate dehydrogenase), which converts the reduced NADH analog cofactor substrate to the oxidized $\mathrm{NAD+}$ analog product. The reduced cofactor absorbs strongly at $408~\mathrm{nm}$ , whereas its oxidized form does not. The rate of decrease in absorbance in the reaction cuvette is proportional to the carbon dioxide content of the sample.
## ACE Direct Bilirubin test:
The ACE Direct Bilirubin test is based on a photometric test. Sodium nitrite, added to sulfanilic acid, forms diazotized sulfanilic acid. Bilirubin glucuronide in serum reacts with diazotized sulfanilic acid to form azobilirubin, which absorbs strongly at 554 nm. The increase in absorbance, one minute after sample addition, is directly proportional to the direct bilirubin concentration in the sample..
## ACE Total Bilirubin test:
The ACE Total Bilirubin test is based on a photometric test. Sodium nitrite, added to sulfanilic acid, forms diazotized sulfanilic acid. Bilirubin glucuronide in serum reacts with diazotized sulfanilic acid to form azobilirubin, which absorbs strongly at 554 nm. The increase in absorbance, five minutes after sample addition, is directly proportional to the total bilirubin concentration in the sample.
## ACE Magnesium test:
The ACE Magnesium test is based on a photometric test. Magnesium ions in serum react with xylidyl blue-1 in an alkaline medium to produce a red complex. The intensity of color produced is directly proportional to the magnesium concentration in the sample. EGTA prevents calcium interference by preferential chelation of calcium present in the sample. A surfactant system is included to remove protein interference.
## M. Performance Characteristics (if/when applicable):
### 1. Analytical performance:
#### a. Precision/Reproducibility:
Precision studies were conducted in house and at three Physician Office Laboratories (POL) with trained operators typically found in these settings, following CLSI guidance document EP5-A2. Three samples each of low, mid and high analyte serum were run on the ACE Alera Clinical Chemistry System in duplicate, for 5 days at 2 runs per day $(N = 40)$ . Results are summarized below:
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| CO2 | | ACE Alera (SD, %CV) | | |
| --- | --- | --- | --- | --- |
| Lab | Sample | Mean (mEq/L) | Within-Run | Total |
| In-House | 1 | 21.1 | 0.43; 2.0 | 0.81; 3.9 |
| POL 1 | 1 | 22.3 | 0.28; 1.3 | 0.67; 3.0 |
| POL 2 | 1 | 22.4 | 0.59; 2.6 | 0.84; 3.8 |
| POL 3 | 1 | 24.3 | 0.37; 1.5 | 1.53; 6.3 |
| In-House | 2 | 24.2 | 0.42; 1.7 | 0.77; 3.2 |
| POL 1 | 2 | 25.6 | 0.32; 1.3 | 0.63; 2.4 |
| POL 2 | 2 | 26.0 | 0.24; 0.9 | 1.00; 3.9 |
| POL 3 | 2 | 27.8 | 0.29; 1.1 | 1.60; 5.8 |
| In-House | 3 | 27.0 | 0.43; 1.6 | 0.83; 3.1 |
| POL 1 | 3 | 28.4 | 0.39; 1.4 | 0.94; 3.3 |
| POL 2 | 3 | 29.3 | 0.48; 1.6 | 0.94; 3.2 |
| POL 3 | 3 | 30.7 | 0.29; 1.0 | 1.60; 5.2 |
| Direct Bili | | ACE Alera (SD, %CV) | | |
| --- | --- | --- | --- | --- |
| Lab | Sample | Mean (mg/dL) | Within-Run | Total |
| In-House | 1 | 1.0 | 0.05; 5.1 | 0.05; 5.4 |
| POL 1 | 1 | 0.9 | 0.04; 4.8 | 0.05; 5.4 |
| POL 2 | 1 | 0.9 | 0.02; 2.5 | 0.02; 2.5 |
| POL 3 | 1 | 0.9 | 0.00; 0.0 | 0.00; 0.0 |
| In-House | 2 | 4.9 | 0.07; 1.5 | 0.09; 1.9 |
| POL 1 | 2 | 4.8 | 0.05; 1.0 | 0.05; 1.0 |
| POL 2 | 2 | 4.8 | 0.07; 1.5 | 0.08; 1.7 |
| POL 3 | 2 | 4.9 | 0.10; 2.0 | 0.10; 2.0 |
| In-House | 3 | 7.8 | 0.20; 2.6 | 0.20; 2.6 |
| POL 1 | 3 | 7.9 | 0.06; 0.8 | 0.07; 0.9 |
| POL 2 | 3 | 7.8 | 0.04; 0.6 | 0.10; 1.3 |
| POL 3 | 3 | 8.0 | 0.08; 1.0 | 0.08; 1.1 |
| Total Bili | | ACE Alera (SD, %CV) | | |
| --- | --- | --- | --- | --- |
| Lab | Sample | Mean (mg/dL) | Within-Run | Total |
| In-House | 1 | 1.2 | 0.05; 4.2 | 0.05; 4.5 |
| POL 1 | 1 | 1.2 | 0.04; 3.2 | 0.04; 3.7 |
| POL 2 | 1 | 1.2 | 0.06; 4.9 | 0.06; 5.0 |
| POL 3 | 1 | 1.1 | 0.05; 4.8 | 0.06; 5.2 |
| In-House | 2 | 11.3 | 0.23; 2.0 | 0.24; 2.1 |
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| POL 1 | 2 | 11.4 | 0.07; 0.7 | 0.09; 0.8 |
| --- | --- | --- | --- | --- |
| POL 2 | 2 | 11.3 | 0.17; 1.5 | 0.17; 1.5 |
| POL 3 | 2 | 11.2 | 0.09; 0.8 | 0.09; 0.8 |
| In-House | 3 | 20.6 | 0.27; 1.3 | 0.35; 1.7 |
| POL 1 | 3 | 20.7 | 0.11; 0.5 | 0.12; 0.6 |
| POL 2 | 3 | 20.5 | 0.11; 0.5 | 0.15; 0.7 |
| POL 3 | 3 | 20.3 | 0.28; 1.4 | 0.28; 1.4 |
| Mg | | ACE Alera (SD, %CV) | | |
| --- | --- | --- | --- | --- |
| Lab | Sample | Mean (mg/dL) | Within-Run | Total |
| In-House | 1 | 1.7 | 0.05; 3.0 | 0.07; 4.5 |
| POL 1 | 1 | 1.7 | 0.07; 4.2 | 0.10; 5.9 |
| POL 2 | 1 | 1.5 | 0.09; 6.0 | 0.13; 8.4 |
| POL 3 | 1 | 1.7 | 0.07; 3.9 | 0.11; 6.5 |
| In-House | 2 | 3.6 | 0.07; 2.0 | 0.09; 2.5 |
| POL 1 | 2 | 3.8 | 0.11; 2.8 | 0.13; 3.6 |
| POL 2 | 2 | 3.5 | 0.10; 2.9 | 0.18; 5.2 |
| POL 3 | 2 | 3.7 | 0.08; 2.1 | 0.13; 3.6 |
| In-House | 3 | 5.5 | 0.05; 1.0 | 0.10; 1.8 |
| POL 1 | 3 | 5.8 | 0.08; 1.4 | 0.12; 2.1 |
| POL 2 | 3 | 5.4 | 0.10; 1.9 | 0.26; 4.8 |
| POL 3 | 3 | 5.5 | 0.05; 0.9 | 0.09; 1.6 |
Additional precision studies were performed in-house using 3 concentrations of lithium heparin plasma samples over a period of 3-5 days. All samples were tested twice a day in duplicate on the ACE, ACE Axcel and ACE Alera Clinical Chemistry Systems. The within-run and total precision results are summarized in the tables below.
| Precision (SD, %CV) | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| CO2 mEq/L | ACE Mean | Within-Run | Total | Alera Mean | Within-Run | Total | Axcel Mean | Within-Run | Total |
| Plasma Low | 22.9 | 0.29, 1.3% | 0.86, 3.8% | 23.3 | 0.71, 3.0% | 1.43, 6.1% | 23.1 | 0.29, 1.3% | 0.86, 3.8% |
| Plasma Mid | 33.7 | 0.41, 1.2% | 1.85, 5.5% | 34.8 | 0.34, 1.0% | 1.77, 5.1% | 33.8 | 0.24, 0.7% | 1.69, 5.0% |
| Plasma High | 45.6 | 0.46, 1.0% | 1.14, 2.5% | 46.9 | 0.46, 1.0% | 1.10, 2.4% | 45.3 | 0.47, 1.0% | 1.05, 2.3% |
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| Precision (SD, %CV) | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Direct Bilirubin mg/dL | ACE Mean | Within-Run | Total | Alera Mean | Within-Run | Total | Axcel Mean | Within-Run | Total |
| Plasma Low | 0.1 | 0.03 | 0.03 | 0.1 | 0.03 | 0.05 | 0.1 | 0.02 | 0.02 |
| Plasma Mid | 4.8 | 0.04, 0.8% | 0.05, 1.1% | 4.8 | 0.08, 1.7% | 0.13, 2.8% | 4.8 | 0.11, 2.4% | 0.11, 2.4% |
| Plasma High | 8.5 | 0.09, 1.1% | 0.14, 1.6% | 8.5 | 0.06, 0.7% | 0.10, 1.1% | 8.5 | 0.16, 1.9% | 0.20, 2.3% |
| Precision (SD, %CV) | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Total Bilirubin mg/dL | ACE Mean | Within-Run | Total | Alera Mean | Within-Run | Total | Axcel Mean | Within-Run | Total |
| Plasma Low | 0.2 | 0.04 | 0.05 | 0.2 | 0.06 | 0.07 | 0.2 | 0.04 | 0.05 |
| Plasma Mid | 13.2 | 0.11, 0.8% | 0.12, 0.9% | 13.0 | 0.13, 1.0% | 0.14, 1.1% | 13.2 | 0.06, 0.5% | 0.07, 0.5% |
| Plasma High | 26.2 | 0.15, 0.6% | 0.17, 0.6% | 25.6 | 0.12, 0.5% | 0.18, 0.7% | 26.1 | 0.13, 0.5% | 0.14, 0.5% |
| Precision (SD, %CV) | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Magnesium mg/dL | ACE Mean | Within-Run | Total | Alera Mean | Within-Run | Total | Axcel Mean | Within-Run | Total |
| Plasma Low | 1.7 | 0.08, 4.7% | 0.11, 6.2% | 1.7 | 0.06, 3.5% | 0.07, 4.1% | 1.7 | 0.04, 2.4% | 0.11, 6.8% |
| Plasma Mid | 3.5 | 0.09, 2.7% | 0.10, 2.8% | 3.5 | 0.09, 2.4% | 0.09, 2.6% | 3.4 | 0.09, 2.8% | 0.13, 3.7% |
| Plasma High | 5.3 | 0.04, 0.9% | 0.10, 1.9% | 5.4 | 0.09, 1.6% | 0.10, 1.8% | 5.3 | 0.05, 1.0% | 0.09, 1.8% |
b. Linearity/assay reportable range:
Serum samples were spiked with the appropriate analyte and used to determine linearity on the ACE Alera Clinical Chemistry System. The assigned values of the highest and lowest sample were set to their mean values. The assigned values of the other levels were calculated by multiplying the mean value by the dilution ratios obtained from the manufacturer. Each level was tested in triplicate. The linear regression correlation between the expected values and the measured values for the CO2 and Mg assays is summarized below:
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| Analyte tested | Linear regression | r2 |
| --- | --- | --- |
| CO2 (mEq/L) | y = 1.006x + 0.01 | 0.9992 |
| Mg (mg/dL) | y = 0.959x + 0.027 | 0.9805 |
For the Direct Bili. and Total Bili. assays, data was analyzed using 1st, 2nd, and 3rd order least square regressions according to CLSI Protocol EP6-A. The third order polynomial regression is the best fit regression. The difference in predicted values between the first and third order models are summarized in the table below:
Direct Bili:
| Sample | Assigned Value (mg/dL) | Mean | Poly. Fit | Line Fit | Deviation from Linearity | % Difference |
| --- | --- | --- | --- | --- | --- | --- |
| 0 | 0.133 | 0.133 | 0.213 | 0.296 | -0.084 | NA |
| 1 | 0.925 | 1.100 | 1.099 | 1.099 | 0.000 | 0.0 |
| 2 | 1.717 | 1.933 | 1.975 | 1.903 | 0.072 | 3.8 |
| 3 | 3.300 | 3.467 | 3.692 | 3.509 | 0.182 | 5.2 |
| 4 | 4.883 | 5.300 | 5.364 | 5.116 | 0.248 | 4.8 |
| 5 | 6.467 | 7.033 | 6.991 | 6.722 | 0.269 | 4.0 |
| 6 | 8.050 | 8.833 | 8.574 | 8.329 | 0.245 | 2.9 |
| 7 | 11.217 | 11.600 | 11.604 | 11.542 | 0.062 | 0.5 |
| 8 | 12.800 | 13.000 | 13.052 | 13.148 | -0.096 | -0.7 |
| 9 | 14.383 | 14.600 | 14.455 | 14.755 | -0.299 | -2.0 |
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Total Bili:
| Sample | Assigned Value (mg/dL) | Mean | Poly. Fit | Line Fit | Deviation from Linearity | % Difference |
| --- | --- | --- | --- | --- | --- | --- |
| 0 | 0.10 | 0.10 | 0.04 | 0.13 | -0.09 | NA |
| 1 | 0.62 | 0.60 | 0.59 | 0.65 | -0.06 | -9.8 |
| 2 | 1.14 | 1.03 | 1.14 | 1.17 | -0.04 | -3.0 |
| 3 | 2.18 | 2.27 | 2.32 | 2.21 | 0.02 | 0.9 |
| 4 | 4.25 | 4.37 | 4.42 | 4.30 | 0.12 | 2.8 |
| 5 | 8.40 | 8.77 | 8.75 | 8.46 | 0.29 | 3.4 |
| 6 | 12.55 | 13.17 | 13.03 | 12.63 | 0.40 | 3.2 |
| 7 | 16.70 | 17.40 | 17.26 | 16.79 | 0.47 | 2.8 |
| 8 | 25.00 | 25.27 | 25.57 | 25.12 | 0.45 | 1.8 |
| 9 | 33.30 | 33.63 | 33.69 | 33.45 | 0.24 | 0.7 |
| 10 | 41.60 | 41.60 | 41.60 | 41.78 | -0.18 | -0.4 |
The linearity data provided by the sponsor support the following reportable range claims:
| Analyte tested | Assay range |
| --- | --- |
| CO2 (mEq/L) | 4 - 50 |
| Direct Bili (mg/dL) | 0.1 – 14 |
| Total Bili (mg/dL) | 0.2 – 40 |
| Mg (mg/dL) | 0.4 – 6.1 |
Automatic dilution study: To examine the accuracy of the auto-dilution function for the ACE Magnesium Reagent, serum and plasma samples were spiked with high concentrations of magnesium and were then either run directly on each of the ACE systems or they were manually diluted 1:3 using system diluent (3 samples per instrument system in triplicate). The results from the auto-dilution and the manually diluted samples, run on the same
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ACE systems, were compared. All samples recovered within $+/-8\%$ bias.
c. Traceability, Stability, Expected values (controls, calibrators, or methods): Traceability: CO2 method is traceable to NIST SRM 351. Total Bilirubin assay is traceable to NIST SRM 916. Direct Bilirubin assay is traceable to gravimetric standards prepared with NIST material. Magnesium method is traceable to NIST SRM 909.
The CO2 standard was previously cleared under k854544. The Direct Bilirubin, Total Bilirubin and Magnesium assay is calibrated using the Gemcal Reference Serum previously cleared under k844344.
# d. Detection limit:
The Limit of blank (LoB), limit of detection (LoD), and limit of quantification (LoQ) were determined according to CLSI EP17-A with the ACE Alera Clinical Chemistry System. For the LoB and LoD studies, low samples and true blanks $(n = 60$ reps, 20 reps per day) were tested over three days on two ACE Alera Clinical Chemistry Systems. For the LoQ studies, samples $(n = 40$ reps, 8 reps per run) were tested in five separate runs over five days. LoQ based on inter-assay precision of $20\%$ CV. The results are as follows:
| Analyte | LoB | LoD | LoQ |
| --- | --- | --- | --- |
| CO2 (mEq/L) | 1.27 | 1.97 | 3.03 |
| Direct Bili (mg/dL) | 0.06 | 0.08 | 0.12 |
| Total Bili (mg/dL) | 0.11 | 0.14 | 0.14 |
| Mg (mg/dL) | 0.26 | 0.37 | 0.37 |
The sponsor claimed the following measuring range:
| Analyte tested | Assay range |
| --- | --- |
| CO2 (mEq/L) | 4 - 50 |
| Direct Bili (mg/dL) | 0.1 – 14 |
| Total Bili (mg/dL) | 0.2 – 40 |
| Mg (mg/dL) | 0.4 – 6.1 |
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# e. Analytical specificity:
Interference studies were performed to determine the effects from potential interferents. The various concentration of interferent was spiked into serum pools containing analytes at normal and abnormal concentrations. All samples were tested in triplicate. Six interferent levels and the control samples were tested for each interferent. Bias greater than $+/- 10\%$ defines significant interference by the sponsor. The results of the highest concentration tested without significant interference are as follows:
| Analyte | Icterus | Hemolysis | Triglycerides | Ascorbic acid |
| --- | --- | --- | --- | --- |
| CO2 (mEq/L) | 58.8 mg/dL | 250 mg/dL | 2388 mg/dL | 6 mg/dL |
| Direct Bili (mg/dL) | NA | 62.5 mg/dL | 782 mg/dL | 6 mg/dL |
| Total Bili (mg/dL) | NA | 62.5 mg/dL | 951 mg/dL | 6 mg/dL |
| Mg (mg/dL) | 50 mg/dL | 500 mg/dL | 620 mg/dL | 6 mg/dL |
Since hemolysis affects Total Bili. and Direct Bili. results, the sponsor has the following limitations in the labeling:
"Specimens showing any indication of hemolysis should not be analyzed."
# f. Assay cut-off:
Not applicable
# 2. Comparison studies:
# a. Method comparison with predicate device:
Method comparison studies were completed at 3 POC sites following CLSI document EP9-A2. Samples were run on the ACE Clinical Chemistry System at Alfa Wassermann and the results were compared against those gathered on ACE Alera Clinical Chemistry Systems at 3 Physician Office Labs. At least 40 determinations were made in singlicate for serum samples drawn from the same individuals on each platform. To test across the assay reportable ranges, additional sets (< 6 sets) of altered samples (spiked or diluted) were used to cover the full measuring range of each analyte. Results are summarized in the table below:
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ACE results (X) vs. ACE Alera results (Y):
| | | Site 1 | Site 2 | Site 3 |
| --- | --- | --- | --- | --- |
| CO2 (mEq/L) | n | 46 | 45 | 45 |
| | Range | 4 to 42.5 | 4 to 46.2 | 4 to 46.2 |
| | Regression | y=0.963x-0.71 | y=0.976x+1.29 | y=0.984x+0.42 |
| | Correlation coefficient | 0.9710 | 0.9530 | 0.9908 |
| Direct Bili (mg/dL) | n | 49 | 49 | 49 |
| | Range | 0.1 to 12.4 | 0.1 to 12.4 | 0.1 to 12.4 |
| | Regression | y=1.022x+0.04 | y=1.003x+0.11 | y=1.012x+0.06 |
| | Correlation coefficient | 0.9986 | 0.9985 | 0.9984 |
| Total Bili (mg/dL) | n | 48 | 50 | 49 |
| | Range | 0.2 to 39.3 | 0.2 to 39.3 | 0.2 to 39.3 |
| | Regression | y=0.979x+0.00 | y=1.000x+0.04 | y=1.000x+0.01 |
| | Correlation coefficient | 0.9995 | 0.9998 | 0.9998 |
| Mg (mg/dL) | n | 51 | 52 | 51 |
| | Range | 0.6 to 6.1 | 0.6 to 6.1 | 0.6 to 6.1 |
| | Regression | y=0.970x+0.12 | y=0.975x+0.16 | y=1.026x-0.04 |
| | Correlation coefficient | 0.9902 | 0.9927 | 0.9925 |
# b. Matrix comparison:
Matrix comparison studies were completed following CLSI guidance document EP9-A2. Samples were tested on the ACE, ACE Alera and ACE Axcel Clinical Chemistry Systems. At least 50 determinations were made in singlicate for paired serum and lithium heparin plasma samples drawn from the same individuals. Of these samples, up to $10\%$ were altered (spiked or diluted) allowing for testing across the assay ranges.
The following charts summarize the matrix comparison studies:
| Reagent | Range | ACE Serum vs. Plasma (Regression Equation and Correlation Coefficient) |
| --- | --- | --- |
| CO2 (mEq/L) 53 pairs | 4.9 to 47.9 | y = 1.031x - 1.03 0.9922 |
| Direct Bili (mg/dL) 102 pairs | 0.1 to 10.8 | y = 1.021x + 0.00 0.9982 |
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| Total Bili (mg/dL) 102 pairs | 0.2 to 37.2 | y = 1.017x + 0.01 0.9996 |
| --- | --- | --- |
| Mg (mg/dL) 101 pairs | 1.2 to 5.8 mg/dL | y = 0.948x + 0.08 0.9703 |
| Reagent | Range | ACE Axcel Serum vs. Plasma (Regression Equation and Correlation Coefficient) |
| --- | --- | --- |
| CO2 (mEq/L) 51 pairs | 5.5 to 47.9 | y = 0.988x - 0.35 0.9889 |
| Direct Bili (mg/dL) 56 pairs | 0.1 to 13.1 | y = 1.004x + 0.00 0.9983 |
| Total Bili (mg/dL) 102 pairs | 0.2 to 35.5 | y =1.008x + 0.00 0.9995 |
| Mg (mg/dL) 56 pairs | 0.6 to 5.6 | y =0.986x + 0.025 0.9892 |
| Reagent | Range | ACE Alera Serum vs. Plasma (Regression Equation and Correlation Coefficient) |
| --- | --- | --- |
| CO2 (mEq/L) 54 pairs | 4.7 to 48.2 | y = 1.000x - 0.09 0.9955 |
| Direct Bili (mg/dL) 101 pairs | 0.1 to 11.0 | y = 1.005x + 0.01 0.9978 |
| Total Bili (mg/dL) 102 pairs | 0.2 to 36.7 | y = 1.020x + 0.00 0.9993 |
| Mg (mg/dL) 101 pairs | 1.0 to 5.9 | y = 0.986x + 0.02 0.9817 |
The sponsor concluded that lithium heparin plasma sample is an acceptable anticoagulant to be used with the assays.
a. Clinical Sensitivity:
Not applicable
b. Clinical specificity:
Not applicable
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c. Other clinical supportive data (when a. and b. are not applicable):
Not applicable
4. Clinical cut-off:
Not applicable
5. Expected values/Reference range:
The following expected values are provided in the product insert based on the literature for each analyte. The sponsor stated that each laboratory should determine the expected values for its particular population.
CO2: 23-29 mEq/L
Direct Bilirubin: <0.2 mg/dL
Total Bilirubin: 0.2-1.0 mg/dL
Mg: 1.6-2.6 mg/dL
Tietz, N.W. (Ed.), Clinical Guide to Laboratory Tests, 4th Edition, W.B. Saunders Co., Philadelphia, PA (2006).
N. Proposed Labeling:
The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.
O. Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.
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