FT4 METHOD FOR THE DIMENSION RXL CLINICAL CHEMISTRY SYSTEM

K971141 · Dade Chemistry Systems, Inc. · CEC · Apr 28, 1997 · Clinical Chemistry

Device Facts

• Record ID: K971141
• Device Name: FT4 METHOD FOR THE DIMENSION RXL CLINICAL CHEMISTRY SYSTEM
• Applicant: Dade Chemistry Systems, Inc.
• Product Code: CEC · Clinical Chemistry
• Decision Date: Apr 28, 1997
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1695
• Device Class: Class 2

Intended Use

The FT4 Method for the Dimension® RxL clinical chemistry system with the heterogeneous immunoassay module is used to quantitatively measure free thyroxine (FT4) in human serum and heparinized plasma.

Device Story

FT4 assay; two-step competitive enzyme immunoassay; performed on Dimension® RxL clinical chemistry system. Input: human serum or heparinized plasma. Process: sample incubated with chromium dioxide particles coated with monoclonal anti-T4 antibodies; magnetic separation of particle/T4 complex; incubation with conjugate reagent; wash step; alkaline phosphatase-triggered amplification cascade; colorimetric measurement at 510nm. Output: colored product concentration inversely proportional to FT4 levels. Used in clinical laboratory settings by trained personnel. Results aid clinicians in assessing thyroid function.

Clinical Evidence

Split sample comparison against Abbott Imx® Free T4 using 156 clinical patient samples. Results: correlation coefficient 0.988, slope 0.963, intercept 0.02 ng/dL.

Technological Characteristics

Competitive enzyme immunoassay; chromium dioxide particles coated with monoclonal antibodies; alkaline phosphatase-based amplification; colorimetric detection at 510nm and 700nm; heterogeneous immunoassay module integration.

Indications for Use

Indicated for the quantitative measurement of free thyroxine (FT4) in human serum and heparinized plasma to aid in the assessment of thyroid function.

Regulatory Classification

Identification

A free thyroxine test system is a device intended to measure free (not protein bound) thyroxine (thyroid hormone) in serum or plasma. Levels of free thyroxine in plasma are thought to reflect the amount of thyroxine hormone available to the cells and may therefore determine the clinical metabolic status of thyroxine. Measurements obtained by this device are used in the diagnosis and treatment of thyroid diseases.

Predicate Devices

• Abbott Laboratories Imx® Free T4

Submission Summary (Full Text)

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DADE
K971141
APR 28 1997
Interoffice Memorandum

# Summary of Safety and Effectiveness Information

This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92.

## Submitter's Name:

Cathy P. Craft
Dade International Inc.
P.O. Box 6101
Newark, DE 19714-6101

## Date of Preparation:

March 27, 1997

## Name of Product:

FT4 Method for the Dimension® RxL Clinical Chemistry System

## FDA Classification Name:

Free Thyroxine Test System

## Predicate Device:

Abbott Laboratories Imx® Free T4

## Device Description:

The FT4 assay is a two-step competitive enzyme immunoassay. Sample is incubated with chromium dioxide particles, coated with monoclonal antibodies specific for FT4 to form a particle/T4 complex. Particles are separated magnetically and the supernatant removed. The particle/T4 complex is incubated with conjugate reagent to react with unoccupied binding sites on the particles. Unbound conjugate is removed by washing. The bound alkaline phosphatase triggers an amplification cascade, resulting in the formation of a colored product. The color change measured at 510nm is inversely proportional to the concentration of free thyroxine present in the patient sample.

## Intended Use:

The FT4 Method for the Dimension® RxL clinical chemistry system with the heterogeneous immunoassay module is used to quantitatively measure free thyroxine (FT4) in human serum and heparinized plasma.

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# Comparison to Predicate

## Device:

| Item | Dimension® RxL FT4 | Imx® Free T4 |
| --- | --- | --- |
| Technology | Competitive format
monoclonal antibody
immunoassay | Competitive format
polyclonal antibody
immunoassay |
| Detection | Colorimetric endpoint
measurement at 510nm
and 700nm | Fluorometric endpoint
measurement |

## Comments on Substantial

**Equivalence:** Split sample comparison between the The FT4 Method for the Dimension® RxL Clinical Chemistry System and the Abbott Imx® Free T4 assay gave a correlation coefficient of 0.988, slope of 0.963, and an intercept of 0.02 ng/dL when tested with 156 clinical patient samples.

**Conclusion:** The The FT4 Method for the Dimension® RxL clinical chemistry system is substantially equivalent in principle and performance to the Imx® Free T4 assay based on the split sample comparison discussed above.


Cathy P. Craft
Regulatory Affairs and Compliance Manager
Date: March 27, 1997