ACA PLUS FREE THYROXINE(FT4) METHOD

K962602 · Dade Intl., Inc. · CEC · Aug 15, 1996 · Clinical Chemistry

Device Facts

• Record ID: K962602
• Device Name: ACA PLUS FREE THYROXINE(FT4) METHOD
• Applicant: Dade Intl., Inc.
• Product Code: CEC · Clinical Chemistry
• Decision Date: Aug 15, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1695
• Device Class: Class 2

Intended Use

The FT4 Method is used in the aca® plus immunoassay system to quantitatively measure free thyroxine (FT4) in human serum and heparinized plasma.

Device Story

One-step competitive enzyme immunoassay for aca® plus system; utilizes chromium dioxide particles coated with monoclonal antibodies specific for FT4 and T3-alkaline phosphatase conjugate. Patient sample added to reaction vessel; particle/FT4/conjugate sandwich forms during incubation. Sandwich washed; transferred to FT4 test pack in aca® discrete clinical analyzer. Bound alkaline phosphatase triggers amplification cascade; colored product formation measured at 510nm. Color intensity proportional to FT4 concentration. Used in clinical laboratory settings by technicians to provide quantitative FT4 results for physician assessment of thyroid status.

Clinical Evidence

Split sample comparison between aca® plus FT4 and IMx® Free T4 using 146 clinical patient samples. Results: correlation coefficient 0.9076, slope 0.94, intercept 0.16.

Technological Characteristics

Competitive enzyme immunoassay; chromium dioxide particle-based solid phase; monoclonal antibody; colorimetric detection at 510nm; discrete clinical analyzer platform.

Indications for Use

Indicated for the quantitative measurement of free thyroxine (FT4) in human serum and heparinized plasma to assess 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
AUG 15 1996
K942602
DADE INTERNATIONAL
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:** 6/28/96
**Name of Product:** aca® plus Free Thyroxine (FT4) Method
**FDA Classification Name:** Free Thyroxine Test System
**Predicate Device:** Abbott Laboratories IMX® Free T4

**Device Description:** The FT4 assay is a one-step competitive enzyme immunoassay. Patient sample is added by the aca® plus to a reaction vessel containing chromium dioxide particles coated with monoclonal antibodies specific for FT4 and T3-alkaline phosphatase conjugate reagent. A particle/FT4/ conjugate sandwich forms during an incubation period. The sandwich is washed to remove any unbound conjugate. The mixture is resuspended and the sandwich is transferred by the aca® plus to an FT4 test pack. The FT4 test pack is then placed into an aca® discrete clinical analyzer.

The bound alkaline phosphatase triggers an amplification cascade, resulting in the formation of a colored product. The color change measured at 510nm is directly proportional to the concentration of free thyroxine present in the patient sample.

**Intended Use:** The FT4 Method is used in the aca® plus immunoassay system to quantitatively measure free thyroxine (FT4) in human serum and heparinized plasma.

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# Comparison to Predicate

## Device:

| Item | aca® plus FT4 | IMx® Free T4 |
| --- | --- | --- |
| Technology | Competitive format
monoclonal antibody
immunoassay | Competitive format
polyclonal antibody
immunoassay |
| Detection | Colorimetric endpoint
measurement at 510nm
and 600nm | Fluorometric endpoint
measurement |

## Comments on Substantial

**Equivalence:** Split sample comparison between the aca® plus FT4 Method and the Imx® Free T4 assay gave a correlation coefficient of 0.9076, slope of 0.94, and an intercept of 0.16 when tested with 146 clinical patient samples.

**Conclusion:** The aca® plus FT4 Method is substantially equivalent in principle and performance to the IMx® Free T4 Assay based on the split sample comparison discussed above.