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Test Code LAB12427 Thyroid-Stimulating Hormone (TSH) w/Reflex to Thyroxine (T4) Free

Department

CHEMISTRY

Primary Collection Container

Gold (SST)

Transport

Serum refrigerated

Preferred Transport Temperature

Refrigerated

Processing

Centrifuge and refrigerate.

Separate from cells if testing is delayed more than 8 hours.

Stability

Refrigerated: 48 hours

Minimum Testing Volume

0.7 mL

Reference Range

TSH:

0.550-4.780 mIU/L

T4 Free (if reflexed):

0.8-1.8 ng/dL

Methodology

Roche e801 Electrochemiluminescence Immunoassay; (TSH) Sandwich principle and (FT4) Competition Principle

Performed

Sunday – Saturday

Reported

As completed

CPT Codes

84443, 84439 if reflexed

Unacceptable Conditions

Gross hemolysis.

Plasma specimens.

Additional Information

Reflexed to T4 Free if TSH is Abnormal.