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Laboratory Medicine

Test catalogue

Thyroid Stimulating Hormone

Test Name

Thyroid Stimulating Hormone

Gold Tube Specimen Type/Requirements

Container Type = 1 Gold Top (Adult) or 1 Lithium Heparin (Baby)

Minimum Testing Volume = 2 ml Blood

Specimen Handling

Collection Instructions: Collect sample in gold top vacutainer(SST) for adult or 2mL green top vacutainer (lithium heparin) for pediatric samples. Ensure sample is well mixed. Write your initials, date and time of collection on the collection label or requisition.

Laboratory Staff Instructions: Only the endocrinology paper requisition has unrestricted access to ordering FT4, FT3. If you get the endocrinology paper requisition and FT4 or FT3 is ticked off, please order it. If you get any other paper requisition that says “FT4, FT3” on it (from any other location, including FHT or emergency), only order the TSH reflex test code. Do not order FT4 or FT3. The reflex will make sure that FT4 or FT3 is measured if TSH is abnormal.

Rejection Criteria: Grossly hemolysed or lipemic specimens, Unlabeled or Not Sufficient Quantity Samples will be rejected.

Stability: Samples is stable for 18hrs at room temperature, 7 days at 2-8°C and 3 months frozen at -20◦C or lower.

Transportation: Send sample to core lab as soon as possible.

Required Documentation

Turnaround Time (TAT)

1 days

Test Utilization

FT4 will only be processed when TSH is
abnormal, and FT3 will be processed
when TSH is low and FT4 is normal.

(Endocrinology has unrestricted access)

Reference Value

0.4 - 5.5 mU/L

Test Code

TSH (Reflex), TSHNR (No-Reflex)

Methodology

Two-Site, Immunoenzymatic Sandwich Assay

Testing Location

SMH-Biochemistry

Other Information

Last Updated: April 05, 2022