Atellica® IM TSH3-Ultra II (TSH3ULII)
Device Facts
| Record ID | K251543 |
|---|---|
| Device Name | Atellica® IM TSH3-Ultra II (TSH3ULII) |
| Applicant | Siemens Healthcare Diagnostics, Inc. |
| Product Code | JLW · Clinical Chemistry |
| Decision Date | Feb 6, 2026 |
| Decision | SESE |
| Submission Type | Traditional |
| Regulation | 21 CFR 862.1690 |
| Device Class | Class 2 |
Indications for Use
The Atellica® IM TSH3-Ultra II (TSH3ULII) assay is for in vitro diagnostic use in the quantitative determination of thyroid-stimulating hormone (TSH, thyrotropin) in human serum and plasma (EDTA and lithium heparin) using the Atellica® IM Analyzer. Measurements of thyroid stimulating hormone produced by the anterior pituitary are used in the diagnosis of thyroid or pituitary disorders.
Device Story
In vitro diagnostic assay for quantitative TSH measurement; utilizes immunologic sandwich principle with direct chemiluminescent detection; input: human serum or plasma samples; processing: anti-FITC monoclonal antibody on paramagnetic particles, FITC-labeled anti-TSH capture antibody, and acridinium ester-labeled anti-TSH tracer antibody; output: quantitative TSH concentration; used on Atellica IM Analyzer in clinical laboratory settings; results interpreted by healthcare providers to diagnose thyroid or pituitary dysfunction.
Clinical Evidence
Bench testing only. Precision/reproducibility evaluated per CLSI EP05-A3 (N=80 per sample for precision; N=225 for reproducibility). Linearity assessed per CLSI EP06 (range 0.004–158.0 μIU/mL). Method comparison (N=323 samples) against predicate showed Passing-Bablok slope 0.97, intercept -0.006, r=0.998. LoB 0.001 μIU/mL, LoD 0.003 μIU/mL, LoQ 0.004 μIU/mL.
Technological Characteristics
Immunologic sandwich assay; direct chemiluminescent detection. Solid phase: paramagnetic particles with anti-FITC and FITC-labeled anti-TSH antibody. Tracer: acridinium ester-labeled anti-TSH antibody. Automated system (Atellica IM Analyzer). Traceable to WHO 3rd IRP 81/565. Sample volume: 75 μL.
Indications for Use
Indicated for quantitative determination of TSH in human serum and plasma to aid in the diagnosis of thyroid or pituitary disorders in patients.
Regulatory Classification
Identification
A thyroid stimulating hormone test system is a device intended to measure thyroid stimulating hormone, also known as thyrotrophin and thyrotrophic hormone, in serum and plasma. Measurements of thyroid stimulating hormone produced by the anterior pituitary are used in the diagnosis of thyroid or pituitary disorders.
Predicate Devices
- ADVIA Centaur® TSH3-Ultra II (TSH3ULII) (K233050)
Related Devices
- K233050 — ADVIA Centaur® TSH3-Ultra II (TSH3ULII) · Siemens Healthcare Diagnostics, Inc. · Apr 4, 2024
Submission Summary (Full Text)
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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
K251543
B Applicant
Siemens Healthcare Diagnostics, Inc.
C Proprietary and Established Names
Atellica® IM TSH3-Ultra II (TSH3ULII)
D Regulatory Information
| Product Code(s) | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| JLW | Class II | 862.1690 - Thyroid Stimulating Hormone Test System | CH - Clinical Chemistry |
## II Submission/Device Overview:
A Purpose for Submission:
Modification of existing device
B Measurand:
Thyroid Stimulating Hormone (TSH)
C Type of Test:
Quantitative, chemiluminescence immunoassay
Food and Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993-0002
www.fda.gov
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K251543.S001 - Page 2 of 8
# III Intended Use/Indications for Use:
## A Intended Use(s):
See Indications for Use below.
## B Indication(s) for Use:
The Atellica® IM TSH3-Ultra II (TSH3ULII) assay is for in vitro diagnostic use in the quantitative determination of thyroid-stimulating hormone (TSH, thyrotropin) in human serum and plasma (EDTA and lithium heparin) using the Atellica® IM Analyzer. Measurements of thyroid stimulating hormone produced by the anterior pituitary are used in the diagnosis of thyroid or pituitary disorders.
## C Special Conditions for Use Statement(s):
Rx-For Prescription Use Only
## D Special Instrument Requirements:
Atellica® IM Analyzer
# IV Device/System Characteristics:
## A Device Description:
The Atellica® IM TSH3ULII assay kit consists of the following reagents:
Ultra-Lite Reagent- bovine serum albumin (BSA) conjugated to monoclonal anti- TSH (~0.3 µg/mL) labeled with acridinium ester in buffer, mouse IgG, BSA, goat serum, sodium azide (< 0.1%); surfactant, and preservatives.
Solid Phase Reagent - anti-fluorescein monoclonal mouse antibody covalently linked to paramagnetic particles (PMP) (~85 µg/mL) in buffer, BSA, goat serum, sodium azide (< 0.1%); surfactant, and preservatives.
Ancillary Well Reagent – Fluorescein isothiocyanate conjugated to monoclonal anti-TSH antibody (~3 µg/mL), BSA, BCG, goat serum, sodium azide (< 0.1%); surfactant, and preservatives.
The Atellica® IM TSH3ULII assay kit is comprised of the following components:
- Ready Pack primary reagent packs containing TSH3ULII Lite Reagent, Solid Phase, and Ancillary Well Reagent
- Atellica® IM TSH3ULII master curve and test definition.
- CAL 3A low calibrator.
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CAL 3A high calibrator.
- Atellica® IM CAL 3A calibrator assigned value sheet.
Materials Required but Not Provided
Atellica® IM Analyzer and system fluids including Atellica® IM Wash, Atellica® IM Acid, Atellica® IM Base and Atellica® IM Cleaner.
## B Principle of Operation:
The Atellica® IM TSH3ULII is a homogeneous, sandwich chemiluminescent immunoassay. 75 μL of sample is incubated with FITC-labeled mouse monoclonal anti-TSH antibody and mouse monoclonal anti-TSH antibody conjugated to BSA. Then FITC-labeled mouse monoclonal anti-TSH antibody and mouse monoclonal anti-fluorescein antibody linked to paramagnetic particles are added and incubated. After washing the immunocomplex with the Atellica® IM wash, Atellica® IM Acid Reagent and Atellica® IM Base Reagent are added to initiate the chemiluminescent reaction. A direct relationship exists between the amount of TSH present in the patient sample and the amount of relative light units (RLUs) detected by the system.
## V Substantial Equivalence Information:
### A Predicate Device Name(s):
ADVIA Centaur® TSH3-Ultra II (TSH3ULII)
### B Predicate 510(k) Number(s):
K233050
### C Comparison with Predicate(s):
| Device & Predicate Device(s): | K251543 | K233050 |
| --- | --- | --- |
| Device Trade Name | Atellica® IM TSH3-Ultra II | ADVIA Centaur® TSH3-Ultra II |
| General Device Characteristic Similarities | | |
| Intended Use/Indications For Use | Quantitative determination of thyroid-stimulating hormone (TSH, thyrotropin) in human serum and plasma. Measurements of thyroid stimulating hormone produced by the anterior pituitary are used in the | Same |
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| Device & Predicate Device(s): | K251543 | K233050 |
| --- | --- | --- |
| | diagnosis of thyroid or pituitary disorders. | |
| Test principle and technology | Chemiluminescence immunoassay | Same |
| Sample Type | Human serum and plasma | Same |
| General Device Characteristic Differences | | |
| Instrument | Atellica® IM Analyzer | ADVIA Centaur® XP system |
| Sample volume | 75 μL | 100 μL |
| Assay Measuring Interval | 0.008–150 μIU/mL (mIU/L) | 0.01–150 μIU/mL (mIU/L) |
| LoQ | 0.004 μIU/L | 0.010 μIU/L |
VI Standards/Guidance Documents Referenced:
Clinical Laboratory Standards Institute (CLSI) EP05-A3: Evaluation of Precision of Quantitative Measurement Procedures; Approved Guideline - Third Edition
CLSI EP09c: Measurement Procedure Comparison and Bias Estimation Using Patient Samples – Third Edition
CLSI EP17-A2: Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures; Approved Guideline - Second Edition
CLSI EP06: Evaluation of the Linearity of Quantitative Measurement – Second Edition
VII Performance Characteristics (if/when applicable):
A Analytical Performance:
1. Precision/Reproducibility:
Precision studies were conducted following the recommendations in CLSI EP05-A3 to estimate repeatability, within-laboratory precision, and reproducibility.
Repeatability and Within-Lab Precision:
The study was conducted using 3 reagent lots of the candidate assay on one Atellica IM analyzer. Six human serum samples, five lithium heparin plasma samples and five controls were tested in duplicate over twenty days, 2 runs per day, 2 replicates per run with for a total of 80 replicates per sample using 3 lots of reagents and one instrument. Repeatability and within laboratory precision were calculated. The within-laboratory SD and %CV includes
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within-run, between-run, and between-day variance components. Results were similar between lots. The results from a representative lot are summarized below.
| | | | Repeatability | | Within-Laboratory Precision | |
| --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean μIU/ml | SD μIU/ml | CV (%) | SD μIU/ml | CV (%) |
| Serum 1 | 80 | 0.091 | 0.0020 | 2.2 | 0.0038 | 4.2 |
| Serum 2 | 80 | 0.205 | 0.0047 | 2.3 | 0.0084 | 4.1 |
| Serum 3 | 80 | 0.519 | 0.0106 | 2.0 | 0.0269 | 5.2 |
| Serum 4 | 80 | 4.846 | 0.1010 | 2.1 | 0.2343 | 4.8 |
| Serum 5 | 80 | 47.864 | 1.4013 | 2.9 | 2.4523 | 5.1 |
| Serum 6 | 80 | 96.779 | 2.9121 | 3.0 | 5.0733 | 5.2 |
| Plasma1 | 80 | 0.102 | 0.0018 | 1.8 | 0.0046 | 4.5 |
| Plasma 2 | 80 | 0.531 | 0.0097 | 1.8 | 0.0293 | 5.5 |
| Plasma 3 | 80 | 4.894 | 0.1173 | 2.4 | 0.2730 | 5.6 |
| Plasma 4 | 80 | 52.592 | 1.3057 | 2.5 | 2.4539 | 4.7 |
| Plasma 5 | 80 | 91.668 | 4.1801 | 4.6 | 6.5350 | 7.1 |
| Control 1 | 80 | 0.110 | 0.0021 | 1.9 | 0.0040 | 3.6 |
| Control 2 | 80 | 0.544 | 0.0080 | 1.5 | 0.0244 | 4.5 |
| Control 3 | 80 | 4.903 | 0.0619 | 1.3 | 0.2364 | 4.8 |
| Control 4 | 80 | 47.588 | 0.7170 | 1.5 | 2.0892 | 4.4 |
| Control 5 | 80 | 100.16 | 1.5253 | 1.5 | 5.0022 | 5.0 |
# Reproducibility:
Six human serum samples, five lithium heparin plasma samples, and controls were tested in replicates of five with one run per day over five days for a total of 225 replicates per sample. Testing was performed using three instruments and three reagent lots. Repeatability, between-day, between-lot, between-instrument, and reproducibility were calculated. The results are summarized below.
| | | Repeatability | | Between-Day | | Between-Lot | | Between-Instrument | | Reproducibility | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | Mean μIU/ml | SD μIU/ml | CV (%) | SD μIU/ml | CV (%) | SD μIU/ml | CV (%) | SD μIU/ml | CV (%) | SD μIU/ml | CV (%) |
| Serum 1 | 0.087 | 0.002 | 2.12 | 0.001 | 1.30 | 0.003 | 3.44 | 0.001 | 1.26 | 0.004 | 4.43 |
| Serum 2 | 0.172 | 0.004 | 2.12 | 0.002 | 1.42 | 0.005 | 2.82 | 0.002 | 0.92 | 0.007 | 3.93 |
| Serum 3 | 0.449 | 0.009 | 2.04 | 0.004 | 0.92 | 0.011 | 2.52 | 0.003 | 0.58 | 0.015 | 3.42 |
| Serum 4 | 4.450 | 0.094 | 2.12 | 0.054 | 1.21 | 0.067 | 1.50 | 0.044 | 0.98 | 0.135 | 3.03 |
| Serum 5 | 53.797 | 1.160 | 2.15 | 0.672 | 1.25 | 1.042 | 1.94 | 0.614 | 1.14 | 1.805 | 3.36 |
| Serum 6 | 100.021 | 2.250 | 2.25 | 1.789 | 1.79 | 3.066 | 3.06 | 0.590 | 0.59 | 4.244 | 4.24 |
| Plasma 1 | 0.090 | 0.002 | 2.23 | 0.001 | 1.07 | 0.003 | 3.54 | 0.002 | 1.86 | 0.004 | 4.70 |
| Plasma 2 | 0.422 | 0.009 | 2.13 | 0.004 | 1.06 | 0.010 | 2.42 | 0.007 | 1.54 | 0.016 | 3.73 |
| Plasma 3 | 4.293 | 0.080 | 1.86 | 0.082 | 1.91 | 0.065 | 1.52 | 0.023 | 0.54 | 0.134 | 3.12 |
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| | | Repeatability | | Between-Day | | Between-Lot | | Between-Instrument | | Reproducibility | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | Mean μIU/ml | SD μIU/ml | CV (%) | SD μIU/ml | CV (%) | SD μIU/ml | CV (%) | SD μIU/ml | CV (%) | SD μIU/ml | CV (%) |
| Plasma 4 | 47.836 | 1.052 | 2.20 | 0.789 | 1.65 | 0.768 | 1.61 | 0.731 | 1.53 | 1.689 | 3.53 |
| Plasma 5 | 98.087 | 2.139 | 2.18 | 2.522 | 2.56 | 2.877 | 2.93 | 1.824 | 1.86 | 4.743 | 4.84 |
| Control 1 | 0.102 | 0.002 | 2.06 | 0.001 | 1.12 | 0.004 | 3.71 | 0.001 | 0.69 | 0.005 | 4.44 |
| Control 2 | 0.506 | 0.008 | 1.63 | 0.005 | 1.08 | 0.013 | 2.57 | 0.003 | 0.59 | 0.017 | 3.28 |
| Control 3 | 4.627 | 0.082 | 1.78 | 0.045 | 0.96 | 0.079 | 1.70 | 0.024 | 0.52 | 0.125 | 2.69 |
| Control 4 | 45.957 | 0.854 | 1.86 | 0.586 | 1.28 | 0.725 | 1.58 | 0.000 | 0.00 | 1.264 | 2.75 |
| Control 5 | 95.579 | 2.007 | 2.06 | 1.228 | 1.26 | 2.508 | 2.57 | 0.000 | 0.00 | 3.439 | 3.52 |
2. Linearity:
A linearity study was performed following CLSI EP06-2 $^{\text{nd}}$ edition. A total of 15 levels of serum samples ranging from 0.004 to 158.0 μIU/ml were prepared by mixing different proportions of a serum sample containing a high concentration of TSH with a serum sample containing a low concentration of TSH. Five replicates of each sample were tested on one Atellica IM Analyzer using 3 reagent lots. The maximum observed deviation within the claimed analytical measuring interval was ±6.5%. The results support the claimed measuring interval of 0.008–150 μIU/mL.
High-Dose Hook Effect: The sponsor evaluated susceptibility to high-dose hook effect. Results are similar to K233050.
3. Analytical Specificity/Interference:
The sponsor provided information to support that analytical specificity is unchanged from what was established in K233050.
4. Detection Limit and Assay Reportable Range:
Detection capability was determined in accordance with CLSI EP17-A2. The studies supported the following detection limit claims:
Limit of Blank (LoB) 0.001 μIU/mL (mIU/L)
Limit of Detection (LoD) 0.003 μIU/mL (mIU/L)
Limit of Quantitation (LoQ) 0.004 μIU/mL (mIU/L)
The LoQ corresponds to the lowest analyte concentration at which the within laboratory CV is ≤ 20%.
The assay reportable range is 0.008 to 150 μIU/mL.
5. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods):
Traceability is unchanged since it was established in K233050.
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Stability: Onboard stability, pack calibration interval, and lot calibration interval studies were completed; the results support the claimed onboard stability, pack calibration interval, lot calibration interval and onboard stability of 63 days.
# 6. Assay Cut-Off:
Not applicable.
# B Comparison Studies:
# 1. Method Comparison with Predicate Device:
A method comparison study was conducted in accordance with CLSI EP09C-Ed3 using 323 human serum samples. Samples were tested in singlicate using 3 reagent lots of the candidate device on the Atellica IM analyzer and tested in singlicate using a single reagent lot of the legally marketed comparator device.
Data were analyzed using Passing-Bablok regression analyses and the differences between the two test systems were evaluated. Results were similar between lots. The results from a representative lot are summarized below.
| N | Sample range* (μIU/ml) | | Slope | Intercept | r |
| --- | --- | --- | --- | --- | --- |
| | Low | High | | | |
| 323 | 0.011 | 147.2 | 0.97 | -0.006 | 0.998 |
*as determined by the comparator method
# 2. Matrix Comparison:
Matrix equivalency between serum and plasma (Lithium Heparin and K2-EDTA) is unchanged since it was established in K233050.
# C Clinical Studies:
# 1. Clinical Sensitivity:
Not applicable.
# 2. Clinical Specificity:
Not applicable.
# 3. Clinical Cut-Off:
Not applicable.
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4. Other Clinical Supportive Data (When 1. and 2. Are Not Applicable):
Not applicable.
D Expected Values/Reference Range:
Expected values are unchanged from when they were established in K233050.
VIII Proposed Labeling:
The labeling supports the finding of substantial equivalence for this device.
IX Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.
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