1881 – SELco^® FT4

Highlights

• Use of free thyroxine (FT4) as the specific target analyte
• Quantitative determination of Tg in human serum
• Provides a reliable indicator of thyroid function, especially in       borderline or conflicting cases
• Competitive assay principle with Iodine-125 labeled monoclonal     antibody
• High precision within the measurement range
• CE marked

Intended Purpose

The SELco® FT4 is a quantitative radioimmunoassay designed for the determination of free thyroxine (FT4) in human serum. This assay is intended as a diagnostic aid for evaluating thyroid function and supporting the identification of thyroid disorders in combination with other clinical and laboratory findings. The SELco® FT4 immunoassay is specifically developed for manual professional in vitro diagnostic use, providing clinicians with a reliable and standardized method for measuring FT4 concentrations. Its high precision and sensitivity allow for accurate monitoring of thyroid function in a variety of clinical scenarios, including routine diagnostics and the follow-up of patients under thyroid therapy.

Diagnostic Relevance

Thyroid hormones, including thyroxine (T4) and triiodothyronine (T3), circulate in two fractions: a major protein-bound fraction and a minor free fraction. The free fraction represents the biologically active hormone. Alterations in total hormone levels may result from changes in serum protein concentrations or hormone synthesis. Persistent changes in the free unbound fraction indicate true thyroid dysfunction. Therefore, measuring FT4 provides a more reliable indicator of thyroid status than total T4 alone. Clinicians use serum FT4 concentrations to assess thyroid secretion and metabolism rates. They recommend FT4 as a critical diagnostic marker, especially in ambiguous, borderline, or conflicting clinical cases. By accurately measuring FT4, the SELco® FT4 assay helps clinicians evaluate thyroid function, detect hypo- or hyperthyroidism, and monitor therapy. This ensures timely and informed clinical decisions.