Click here for more information about laboratory operations and procedures
Free T3, Adult
| Item | Value | ||
|---|---|---|---|
| Test Update Information | Effective March 19, 2013, the Free T3 assay changed from the Abbott Axsym to the Abbott Architect i2000 analyzer. NOTE new reference range and change in units of measurement from pg/dL to pmol/L. Conversion formula: (Concentration in pg/dL) x (.01536)= concentration in pmol/L | ||
| Approval req'd? | No | ||
| Available Stat? | No | ||
| Test code | FT3 | ||
| Test group | Thyroid tests | ||
| Performed by | China Basin Chemistry | ||
| In House Availability | Monday - Saturday (day shift) | ||
| Method | Two step chemiluminescent Microparticle Immunoassay (Abbott Architect i2000) | ||
| Container type | Gold top or Light Green top | ||
| Amount to Collect | 2 mL blood | ||
| Sample type | Serum or plasma | ||
| Preferred volume | 1 mL serum or plasma | ||
| Min. Volume | 0.5 mL serum or plasma | ||
| Processing notes | Refrigerate | ||
| Units | pmol/L | ||
| Normal range |
For children, order test Free T3, Pediatric (code PFT3) Adult reference ranges adopted from manufacturer reference range studies (95% CI) and verified in-house using blood donor (N=124) (excluding autologous donors) on no medications and negative for anti-Tg and TPO antibodies. |
||
| Synonyms | Triiodothyronine | ||
| Turn around times | 1 day | ||
| Additional information | T3 circulates in the blood as an equilibrium mixture of free and protein bound hormone. T3 is bound to thyroxine binding globulin (TBG), prealbumin, and albumin. The binding of these proteins is such that only 0.2-0.4% of the total T3 is present in solution as unbound or free T3. This free fraction represents the physiologically active thyroid hormone. Occasionally, FT3 alone is elevated (T3 thyrotoxicosis) in about 5% of the hyperthyroid population. FT3 may also be important in monitoring patients on antithyroid therapy where treatment is focused on reducing the T3 production and the T4 conversion to T3. Serum FT3 may also be useful in assessing the severity of the thyrotoxic state. | ||
| Medical Necessity? | Yes. Click here for more information | ||
| LOINC code | 3051-0 | ||
| Last Updated | 5/30/2013 9:57:09 AM | ||
| Entry Number | 1038 | ||
| Lab Procedure Link | Click here for Procedure |
If you have additional questions regarding this test, please call: 415-353-1667