← Product Code [LDP](/productcode/LDP) · K261364

# Atellica CH Acetaminophen 2 (ACTM) (K261364)

_Siemens Healthcare Diagnostics, Inc. · LDP · Jul 24, 2026 · Clinical Toxicology · SESE_

**Canonical URL:** https://fda-staging.innolitics.com/device/K261364

## Device Facts

- **Applicant:** Siemens Healthcare Diagnostics, Inc.
- **Product Code:** [LDP](/productcode/LDP.md)
- **Decision Date:** Jul 24, 2026
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 862.3030
- **Device Class:** Class 2
- **Review Panel:** Clinical Toxicology

## Indications for Use

The Atellica CH Acetaminophen 2 (ACTM) assay is for in vitro diagnostic use in the quantitative determination of acetaminophen in human serum and plasma (K2 EDTA, lithium heparin, sodium heparin) using the Atellica CH Analyzer. Measurements obtained by this device are used in the diagnosis and treatment of acetaminophen overdose.

## Device Story

Atellica CH Acetaminophen 2 (ACTM) is an in vitro diagnostic assay for quantitative acetaminophen measurement in human serum and plasma. Used on the Atellica CH Analyzer in clinical laboratory settings. Principle: enzymatic hydrolysis of acetaminophen by arylacylamidase to p-aminophenol and acetate; p-aminophenol reacts with ethyl-N-(3-sulfopropyl)-m-anisidin and periodate catalyst to form an indophenol derivative. Colorimetric measurement at 694/545 nm; absorbance proportional to acetaminophen concentration. Output provides quantitative concentration values to clinicians for diagnosing and managing acetaminophen overdose.

## Clinical Evidence

No clinical data. Performance established via bench testing, including precision (repeatability CV 0.3-1.5%), linearity (2.0–200 µg/mL), and method comparison against the predicate using 104 patient samples. Interference testing performed per CLSI EP07 and EP37; LoB/LoD/LoQ determined per CLSI EP17-A2.

## Technological Characteristics

Enzymatic colorimetric assay. Reagents: Sodium periodate, Arylacylamidase, Ethyl-N-(3-sulfopropyl)-m-anisidin. Measurement: 694/545 nm. Measuring range: 2.0–200 µg/mL (extendable to 600 µg/mL via auto-dilution). Traceability: ISO 17511:2020. Standards: CLSI EP05-A3, EP06, EP07, EP09c, EP17-A2, EP34.

## Regulatory Identification

An acetaminophen test system is a device intended to measure acetaminophen, an analgestic and fever reducing drug, in serum. Measurements obtained by this device are used in the diagnosis and treatment of acetaminophen overdose.

## Predicate Devices

- Emit tox Acetaminophen ([K002974](/device/K002974.md))

## Submission Summary (Full Text)

> This content was OCRed from public FDA records by [Innolitics](https://innolitics.com). If you use, quote, summarize, crawl, or train on this content, cite Innolitics at https://innolitics.com.
>
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FDA

U.S. FOOD & DRUG

ADMINISTRATION

# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION

# DECISION SUMMARY

ASSAY ONLY

# I Background Information:

A 510(k) Number

K261364

B Applicant

Siemens Healthcare Diagnostics, Inc.

C Proprietary and Established Names

Atellica CH Acetaminophen 2 (ACTM)

D Regulatory Information

|  Product Code(s) | Classification | Regulation Section | Panel  |
| --- | --- | --- | --- |
|  LDP | Class II | 21 CFR 862.3030 Acetaminophen Test System | Toxicology  |

# II Submission/Device Overview:

A Purpose for Submission:

New Device

B Measurand:

Acetaminophen

C Type of Test:

Quantitative enzymatic / colorimetric assay

# III Intended Use/Indications for Use:

A Intended Use(s):

Food and Drug Administration

10903 New Hampshire Avenue

Silver Spring, MD 20993-0002

www.fda.gov

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See Indications for Use below.

# **B Indication(s) for Use:**

The Atellica CH Acetaminophen 2 (ACTM) assay is for in vitro diagnostic use in the quantitative determination of acetaminophen in human serum and plasma (K2 EDTA, lithium heparin, sodium heparin) using the Atellica CH Analyzer. Measurements obtained by this device are used in the diagnosis and treatment of acetaminophen overdose.

# **C Special Conditions for Use Statement(s):**

Rx – For Prescription Use Only

# **D Special Instrument Requirements:**

Atellica CH Analyzer

# **IV Device/System Characteristics:**

# **A Device Description:**

The assay consists of the following reagents:

|  Component | Active Ingredients | Volume  |
| --- | --- | --- |
|  Reagent 1 | Sodium periodate (1.88 mmol/L) | 23.4 mL  |
|  Reagent 2 | Arylacylamidase (>6,000 U/L); Ethyl-N-(3-sulfopropyl)m-anisidin (10 mmol/L) | 13.5 mL  |

# **B Principle of Operation:**

The Acetaminophen assay is an enzymatic assay based on the hydrolysis of acetaminophen by arylacylamidase to p-aminophenol and acetate. In the presence of ethyl-N-(3-sulfopropyl)-m-anisidin and a periodate catalyst, the p-aminophenol is converted to an indophenol derivative, and the reaction is measured colorimetrically at 694/545 nm. The increased absorbance at 694/545 nm is directly proportional to the concentration of acetaminophen in the sample.

# **V Substantial Equivalence Information:**

# **A Predicate Device Name(s):**

Emit Tox Acetaminophen

# **B Predicate 510(k) Number(s):**

K002974

# **C Comparison with Predicate(s):**

|  **Device & Predicate Device(s):** | K261364 (Candidate) | K002974 (Predicate)  |
| --- | --- | --- |

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|  Device Trade Name | Atellica CH Acetaminophen 2 (ACTM) | Emit Tox Acetaminophen  |
| --- | --- | --- |
|  **General Device Characteristic Similarities**  |   |   |
|  Intended Use/Indications For Use | For in vitro diagnostic use in the quantitative determination of acetaminophen in human serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of acetaminophen overdose. | Same  |
|  **General Device Characteristic Differences**  |   |   |
|  Measurement Range | 2.0 – 200 µg/mL | 0.25 – 200 µg/mL  |
|  Methodology | Enzymatic (arylacylamidase) coupled with colorimetric measurement at 694/545 nm | Enzyme immunoassay coupled with spectrophotometric measurement at 340 nm.  |
|  Sample Type | Serum and Plasma (K2 EDTA lithium heparin, sodium heparin) | Serum and Plasma (EDTA, heparin, citrate and oxalate/fluoride)  |

## VI Standards/Guidance Documents Referenced:

- CLSI EP17-A2 2nd Edition: *Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures*, FDA Recognition Number: 7-233
- CLSI EP05-A3: *Evaluation of Precision Performance of Quantitative Measurement Methods*, FDA Recognition Number: 7-251
- ISO 17511 2nd Edition: *In vitro diagnostic medical devices - Requirements for establishing metrological traceability of values assigned to calibrators, trueness control materials and human samples*, FDA Recognition Number: 7-305
- CLSI EP09c 3rd Edition: *Measurement Procedure Comparison and Bias Estimation Using Patient Samples*, FDA Recognition Number: 7-296
- CLSI EP06 2nd Edition: *Evaluation of the Linearity of Quantitative Measurement Procedures*, FDA Recognition Number: 7-306
- CLSI EP07 3rd Edition: *Interference Testing in Clinical Chemistry*, FDA Recognition Number: 7-275

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- CLSI EP34 1st Edition: Establishing and Verifying an Extended Measuring Interval Through Specimen Dilution and Spiking, FDA Recognition Number: 7-290
- CLSI EP25 2nd Edition: Evaluation of Stability of In Vitro Medical Laboratory Test Reagents FDA Recognition Number: 7-318 I

# VII Performance Characteristics (if/when applicable):

# A Analytical Performance:

# 1. Precision/Reproducibility:

Precision studies were performed using one pooled serum samples and three individual unique serum samples each spiked with acetaminophen. Samples were assayed in duplicate (2), with two runs per day for 20 days on one reagent lot and one Atellica CH Analyzer for analyses of repeatability, between-run, between-day and within-lab precision. Between-lot, between-instrument precision and reproducibility were also assessed by testing replicates of five (5), one run per day, for five days using three reagent lots on three Atellica CH analyzers. Summary of precision results are shown below.

|  Serum Sample | N | Mean (μg/mL) | Repeatability |   | Between-Run |   | Between-Day |   | Within-Lab  |   |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|   |   |   |  SD (μg/mL) | CV (%) | SD (μg/mL) | CV (%) | SD (μg/mL) | CV (%) | SD (μg/mL) | CV (%)  |
|  1 | 80 | 4.7 | 0.07 | 1.5 | 0.07 | 1.5 | 0.11 | 2.3 | 0.15 | 3.2  |
|  2 | 80 | 45.3 | 0.18 | 0.4 | 0.19 | 0.4 | 0.67 | 1.5 | 0.71 | 1.6  |
|  3 | 80 | 165.1 | 0.48 | 0.3 | 0.5 | 0.3 | 2.26 | 1.4 | 2.37 | 1.4  |
|  4 | 80 | 98.1 | 0.29 | 0.3 | 0.38 | 0.4 | 1.33 | 1.4 | 1.42 | 1.4  |

|  Serum Sample | N | Mean (μg/mL) | Between-Lot |   | Between-Instrument |   | Reproducibility  |   |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|   |   |   |  SD (μg/mL) | CV (%) | SD (μg/mL) | CV (%) | SD (μg/mL) | CV (%)  |
|  1 | 225 | 4.6 | 0.06 | 1.3 | 0.11 | 2.4 | 0.2 | 4.3  |
|  2 | 225 | 44.4 | 0.13 | 0.3 | 0.29 | 0.7 | 0.41 | 0.9  |
|  3 | 225 | 162.3 | 0.55 | 0.3 | 1.06 | 0.7 | 1.37 | 0.8  |
|  4 | 225 | 96.4 | 0.17 | 0.2 | 0.59 | 0.6 | 0.85 | 0.9  |

# 2. Linearity:

Linearity for the Atellica CH Acetaminophen 2 ACTM assay was assessed following CLSI EP06 2nd ED: Evaluation of Linearity of Quantitative Measurement Procedures. A dilution series of nine (9) levels was prepared by mixing a high serum specimen that was spiked with acetaminophen and a blank serum specimen not containing the analyte. Each resulting acetaminophen level (1.7, 6.0, 10.0, 30.0, 60.0, 90.0, 120.0, 150.0, and 210.0 μg/mL) was assayed in replicates of four using one reagent lot, on one Atellica CH analyzer.

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The maximum deviation within the reportable range was -1.8 µg/mL or 3.0%. The results of the linearity studies support the sponsor’s claimed measuring interval of 2.0 – 200 µg/mL.

#### Auto Dilution Validation

Dilution accuracy was evaluated following CLSI EP34 to extend the measurement range to 600 µg/mL. Acetaminophen concentrations between 262.0 to 543.6 µg/mL were prepared by spiking five serum specimens with known acetaminophen. The acetaminophen concentration of each sample was assigned by assaying on the predicate device. Each sample was automatically diluted at a 1:3 dilution and run in replicates of 5 using one reagent lot on two instruments. The % recovery were all within ± 7% of the expected value.

### 3. Analytical Specificity/Interference:

Interference studies were performed as described in CLSI EP07 3$^{rd}$ ED: Interference Testing in Clinical Chemistry and CLSI EP37 1$^{st}$ ED: Supplemental Tables for Interference Testing in Clinical Chemistry.

Matched test control samples were prepared for each potential interferent by spiking native human serum containing acetaminophen concentrations at approximately 7.5 – 12.5 µg/mL and 22.5 – 37.5 µg/mL and tested in replicates of five. The highest interferent concentration tested that results in interference ≤10% or within ±2 µg/mL is determined as the concentration with no significant interference.

#### *Endogenous Interference*

|  Potential Endogenous Interferent | Highest Tested Interferent Concentration with no significant interference (mg/dL)  |
| --- | --- |
|  Bilirubin – conjugated | 60  |
|  Bilirubin – unconjugated | 30  |
|  Hemoglobin | 500  |
|  Lipemia (Intralipid) | 500  |
|  Lipemia (from human triglyceride fraction) | 1500  |
|  Total Protein | 10 g/dL  |

#### *Exogenous Interference*

|  Interferent | Highest Tested Interferent Concentration with no significant interference  |
| --- | --- |
|  |   |

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|  Acetylsalicylic Acid | 117.3 mg/dL  |
| --- | --- |
|  Amitriptyline | 0.1 mg/dL  |
|  Ampicillin | 33.3 mg/dL  |
|  Benzocaine | 560 mg/L  |
|  Cefoxitin | 69 mg/dL  |
|  Codeine | 0.141 mg/dL  |
|  Cyclosporine | 1.2 mg/dL  |
|  Cysteamine | 220 µmol/L  |
|  Dapsone | 5.9 mg/L  |
|  Dipyrone/Metamizole | 10 mg/dL  |
|  2,5-Dihydroxybenzoic acid | 117 µmol/L  |
|  Doxycycline | 4.5 mg/dL  |
|  Ibuprofen | 50 mg/dL  |
|  Imipramine | 0.0315 mg/dL  |
|  L-Ascorbic Acid | 324 mg/dL  |
|  L-Cysteine | 1 mg/mL  |
|  Levodopa | 0.75 mg/dL  |
|  L-Methionine | 500 µg/mL  |
|  Methyldopa | 2.25 mg/dL  |
|  Metoclopramide | 0.225 mg/dL  |
|  Metronidazole | 12.3 mg/dL  |
|  N-Acetylcysteine | 100 mg/dL  |
|  N-Acetylprocainamide | 4.8 mg/dL  |
|  NAPQI (N-Acetyl-4-benzoquinoneimine) | 0.375 mg/dL  |
|  p-Aminosalicylic acid | 81.2 mg/dL  |
|  Phenylbutazone | 89.1 mg/dL  |
|  Procainamide | 4.8 mg/dL  |
|  Rifampicin | 7.5 mg/dL  |
|  Salicylic acid | 60.8 mg/dL  |
|  Tetracycline | 2.4 mg/dL  |
|  Theophylline | 6 mg/dL  |

#### 4. Detection Limit and Assay Reportable Range:

The Limit of Blank (LoB), Limit of Detection (LoD), and Limit of Quantitation (LoQ) were determined in accordance with CLSI EP17-A2.

The LoB and LoD were each determined using four samples (blank samples and low-level samples, respectively) assayed in five replicates per day over three days, across three reagent lots, yielding 60 total measurements per reagent lot.

The LoB for each reagent lot was calculated nonparametrically as the value at the 95th percentile of the ranked blank sample measurement results. The overall assay LoB was defined as the maximum LoB observed across all three reagent lots.

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The LoD for each reagent lot was calculated parametrically using the following equation: $$\text{LoD} = \text{LoB} + \text{cp} \times \text{SDL}$$ where cp is the correction factor derived from the 95th percentile of the standard normal (Gaussian) distribution, and SDL is the pooled standard deviation of measurement results across all low-level samples. The overall assay LoD was defined as the maximum LoD observed across all three reagent lots.

The LoQ was determined using five samples assayed in replicates of eight over five days on three reagent lots yielding a total of 40 measurements per sample per reagent lot. LoQ for each reagent lot was defined as the lowest analyte concentration at which the within-laboratory coefficient of variation (CV) was ≤ 15% or the LoD, whichever was greater. The largest LoQ calculated among the lots was the overall assay LoQ.

|  LoB | 0.1 μg/mL  |
| --- | --- |
|  LoD | 0.5 μg/mL  |
|  LoQ | 2.0 μg/mL  |

# 5. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods):

The Atellica CH Acetaminophen ACTM calibrator is traceable to an internal standard manufactured using United State Pharmacopeia reference standard. Traceability was established following ISO 17511:2020.

Studies support the following claims:

|   | Claim  |
| --- | --- |
|  Pack Calibration | 3 days  |
|  Lot Calibration | 30 days  |
|  On-board Stability | 15 days  |

# 6. Assay Cut-Off:

Not applicable

# B Comparison Studies:

# 1. Method Comparison with Predicate Device:

A method Comparison study was performed in accordance with CLSI EP09c-ED3. A total of 104 native human serum patient samples ranging from 2.1 – 181.6 μg/mL were tested using the candidate device on the Atellica CH analyzer and the predicate device.

Deming regression analysis resulted in a slope of 1.00 μg/mL, y-intercept of 0.10 μg/mL and a correlation coefficient of 0.998.

# 2. Matrix Comparison:

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A matrix comparison study was conducted for serum, lithium heparin plasma, sodium heparin plasma, and K2 EDTA plasma. Matched samples set from the same donor were drawn into four different tube types: serum, lithium heparin plasma, sodium heparin plasma, and K2 EDTA plasma. A total of 51 samples were assayed using one reagent lot over seven days. Specimen equivalence was evaluated by Deming regression analysis comparing serum to lithium heparin plasma, sodium heparin plasma, and K2 EDTA plasma.

|  Comparative Specimen Type (X) | Candidate Specimen Type (Y) | Sample Range (μg/mL) | N | Regression Equation (μg/mL) | r  |
| --- | --- | --- | --- | --- | --- |
|  Serum | Lithium Heparin Plasma | 3.7 - 184.7 | 51 | Y = 1.01X - 0.1 | 1.00  |
|   |  Sodium Heparin Plasma | 3.7 - 184.7 | 51 | Y = 1.00X - 0.1 | 1.00  |
|   |  K2 EDTA Plasma | 3.7 - 184.7 | 51 | Y = 1.01X - 0.5 | 1.00  |

### C Clinical Studies:

1. Clinical Sensitivity:

Not applicable

2. Clinical Specificity:

Not applicable

3. Clinical Cut-Off:

Not applicable

4. Other Clinical Supportive Data (When 1. and 2. Are Not Applicable):

Not applicable

### D Expected Values/Reference Range:

Expected values were cited from Rifai, Nader, Horvath Andrea Rita, Wittwer Carl T. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:1801.

|  Expected Values/Reference Range | Concentrations (μg/mL)  |
| --- | --- |
|  Therapeutic Range | 10 - 30  |
|  Toxic Concentration 4 hours post-ingestion | >200  |
|  Toxic Concentration 12 hours post-ingestion | >50  |

### VIII Proposed Labeling:

The labeling supports the finding of substantial equivalence for this device.

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# **IX Conclusion:**

The submitted information in this premarket notification is complete and supports a substantial equivalence decision.

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**Source:** [https://fda-staging.innolitics.com/device/K261364](https://fda-staging.innolitics.com/device/K261364)

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