Total Triiodothyronine Competitive Immunoassay for Thyroid Function Assessment
The Sekbio TT3 CLIA Bulk Reagent enables quantitative measurement of Total Triiodothyronine (TT3 / Total T3) — the biologically active thyroid hormone critical for metabolic regulation, cardiovascular function, and neurodevelopment. TT3 measurement, alongside TT4, fT3, fT4, and TSH, forms the comprehensive thyroid function panel for diagnosing hyperthyroidism, hypothyroidism, and thyroid hormone binding abnormalities.
Uses a two-step competitive immunoassay format on the AE chemiluminescence platform (Ra magnetic bead + Rc biotin + Rd AE). Calibration range 0–9.18 nmol/L covers the full TT3 reference interval (1.2–2.7 nmol/L) through hyperthyroid elevations. Within-run CV ≤6.8% meets clinical precision requirements.
Two-step competitive: Step 1 — 30µL Rd + 30µL sample, 10 min (no wash); Step 2 — 30µL Ra + 30µL Rc, 5 min, wash; read RLU.
Inverse dose-response characteristic of competitive assay — RLU decreases with increasing TT3 concentration. S/N defined as highest calibrator (0 nmol/L blank) divided by lowest calibrator RLU.
| Calibrator (nmol/L) | RLU Run 1 | RLU Run 2 | RLU Run 3 | Avg RLU | Relative Signal |
|---|---|---|---|---|---|
| 0 (Max signal) | 1,933,505 | 1,974,955 | 1,999,301 | 1,969,254 | 1.00× |
| 0.43 | 1,210,196 | 1,222,332 | 1,193,793 | 1,208,774 | 0.61× |
| 1.83 | 552,028 | 526,336 | 530,569 | 536,311 | 0.27× |
| 2.91 | 351,150 | 346,261 | 359,481 | 352,297 | 0.18× |
| 4.71 | 305,696 | 303,464 | 308,233 | 305,798 | 0.16× |
| 9.18 (Min signal) | 217,174 | 213,542 | 215,716 | 215,477 | 0.11× |
| Competitive assay: signal decreases with analyte concentration. S/N ratio (0/9.18 nmol/L) = 9.14. | |||||
| QC Level (nmol/L) | Avg Conc (nmol/L) | SD | CV |
|---|---|---|---|
| 1.83 (Low) | 1.73 | 0.115 | 6.66% |
| 4.71 (High) | 4.00 | 0.272 | 6.79% |
| n=10 replicates per level. Acceptance criterion: CV ≤10%. | |||
Elevated TT3 (>2.7 nmol/L) is the primary marker for T3 thyrotoxicosis — where T3 is elevated while T4 may be normal. TT3 assay essential for Graves' disease workup and toxic nodular goiter evaluation.
TT3 paired with TT4, fT3, fT4, and TSH forms the comprehensive thyroid function panel. Competitive CLIA format enables same-platform, same-analyzer thyroid profile automation.
TT3 falls in non-thyroidal illness (euthyroid sick syndrome) — monitoring TT3 alongside reverse T3 and TSH helps distinguish primary thyroid disease from systemic illness effects on thyroid hormones.
TT3 bulk reagent (Ra + Rc + Rd) for CLIA analyzer integration. Competitive format for small molecules. Available with TT4, fT3, fT4 pairs for complete thyroid panel OEM supply.
Technical datasheets, performance data, and OEM pricing available on request.