(56 days)
Immunoassay for the in vitro quantitative determination of total thyroxine in human serum and plasma.
The Elecsys® test principle is based on competition principle. Total duration of assay: 18 minutes (37°C).
• 1st incubation (9 minutes): Sample (15 µL) and a specific anti-T4 antibody labeled with a ruthenium complex (75 uL).
• 2nd incubation (9 minutes): After addition of biotinylated T4 (75 uL) and streptavidin-coated microparticles (35 uL), the still-free binding sites of the labeled antibody become occupied, with formation of an antibody-hapten complex. The entire complex is bound to the solid phase via interaction of biotin and streptavidin.
•The reaction mixture is aspirated into the measuring cell where the microparticles are magnetically captured onto the surface of the electrode. Unbound substances are then removed with ProCell. Application of a voltage to the electrode then induces chemiluminescent emission which is measured by a photomultiplier (0.4 second read frame).
•Results are determined via a calibration curve which is instrument-specifically generated by 2-point calibration and a master curve provided via the reagent bar code.
The provided document is a 510(k) summary for the Elecsys® T4 Assay, an in vitro diagnostic device for the quantitative determination of total thyroxine in human serum and plasma. This type of document is used to demonstrate substantial equivalence to a predicate device, not necessarily to set and meet acceptance criteria in the same way a clinical study for a novel therapeutic might.
However, we can infer "acceptance criteria" from the comparative performance tables against the predicate device, the Enzymun T4 Assay (K901346). The study aims to show that the Elecsys® T4 Assay performs comparably or better than the predicate device across various metrics.
Here's an attempt to structure the information based on your request, using the available data:
Acceptance Criteria and Device Performance Study for Elecsys® T4 Assay
The study presented in the 510(k) summary compares the performance of the Elecsys® T4 Assay to its predicate device, the Enzymun T4 Assay (K901346). The "acceptance criteria" are implied by the performance characteristics of the predicate device, with the new device aiming to demonstrate comparable or improved performance.
1. Table of Acceptance Criteria (Implied) and Reported Device Performance
| Feature | Implied Acceptance Criteria (Predicate: Enzymun T4 Assay) | Reported Device Performance (Elecsys® T4 Assay) |
|---|---|---|
| Precision | Modified NCCLS (nmol/L): | |
| (Within-Run %CV) | Control 1: 2.3% | Control 1: 2.3% |
| Control 2: 2.0% | Control 2: 2.0% | |
| Low: 2.3% | Low: 2.3% | |
| Mid: 2.4% | Mid: 2.4% | |
| High: 2.0% | High: 2.0% | |
| (Total %CV) | Control 1: 3.3% | Control 1: 3.3% |
| Control 2: 2.7% | Control 2: 2.7% | |
| Low: 3.1% | Low: 3.1% | |
| Mid: 2.9% | Mid: 2.9% | |
| High: 2.5% | High: 2.5% | |
| Lower Detection Limit | 0.6 µg/dL (7.7 nmol/L) | 0.23 µg/dL (3 nmol/L) |
| Linearity | 0.6 - 25.0 µg/dL (±10% deviation) | 0.23 - 24.86 µg/dL (±10% deviation) |
| Method Comparison | Least Squares (vs Enzymun-Test® T4): | Least Squares (vs Enzymun-Test® T4): |
| (Correlation) | r = 0.996 | r = 0.947 |
| Interfering Substances | ||
| Bilirubin | No interference at 64.5 mg/dL | No interference at 25 mg/dL |
| Hemoglobin | No interference at 1 g/dL | No interference at 1 g/dL |
| Lipemia | No interference at 1250 mg/dL | No interference at 1500 mg/dL |
| Biotin | No interference at 200 ng/mL | No interference at 30 ng/mL |
| Specificity (% Cross-reactivity) | ||
| L-T4 | 100 | 100 |
| D-T4 | 100 | 100 |
| L-T3 | 3.5 | 1.53 |
| D-T3 | 2.9 | 1.38 |
| 3-iodo-L-tyrosine |
§ 862.1700 Total thyroxine test system.
(a)
Identification. A total thyroxine test system is a device intended to measure total (free and protein bound) thyroxine (thyroid hormone) in serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of thyroid diseases.(b)
Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.