Thyroglobulin

The NACB Guidelines state that any laboratory testing for Thyroglobulin MUST also determine the TgAb status of that patient’s sera. The new NACB guidelines also suggest that laboratories archive specimen left after serum Tg measurement for at least 6months. This allows for concurrent re-measurement of the past and current specimens in the same run - a maneuver that eliminates the between-run error and improved the clinical sensitivity of the test. USC lab stores Tg sera indefinitely. *(Thyroid 13:57-67, 2003)

Large Red Top; Serum

Aliquot tube, 2ml serum

Stored at 2 - 8°C until used; Stable if frozen at - 20°C. Studies indicate that Tg in serum is remarkably stable even at ambient temperature if there are no losses due to evaporation. Samples are usually stored at 2 - 8°C for up to one week. For long-term storage, freezing samples at -10 to -20°C is preferred. Repeat thawing and freezing of samples does not influence values if there are no losses due to evaporation.

grossly hemolyzed or lipemic samples are not acceptable.

IMA: Monday - Friday

RIA: Tuesday - Friday

IMA: 2 dys

RIA: 6 days

REFERENCE RANGE FOR FNAW
<1.0 ng/mL

REFERENCE RANGE FOR SERUM

*Tg Reference Ranges with TSH Correlation            Tg                   TSH 

Normal Thyroid                                                     (3 – 40 ng/mL)           (0.30 - 4.00 mIU/L)

Normal Thyroid (suppressed TSH)                           (1.5 – 20 ng/mL)        (<0.1 mIU/L)

Post Lobectomy (normal TSH)                               (1.5 – 20 ng/mL)        (0.30 - 4.00 mIU/L)

Near-Total Thyroidectomy (suppressed TSH)         (<2 ng/mL)                 (<0.1 mIU/L)

Goiter (thyriod enlarged)                                        (>40 ng/mL)