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Test Code TSH Thyroid-Stimulating Hormone (TSH), Plasma or Serum

Important Note

  Many dietary supplements promoted for hair, skin, and nail benefits contain Biotin (Vitamin B7) levels up to 650 times the recommended daily intake.  High levels of Biotin can cause clinically significant incorrect lab test results, resulting in falsely high or falsely low results, depending on the test. Patients taking high doses of Biotin should be instructed to discontinue Biotin for at least 12 hours prior to lab testing.

WARNING: Do not use samples that contain fluorescein (angiography)

Performing Laboratory

MaineGeneral Medical Center

Reference Values

Adults:  >20 years:  0.360-3.740 mIU/mL

              13-20 years: 0.463-4.130 mIU/mL

               2-12 years: 0.662-4.010 mIU/mL

  Infants  less than24 months  0.816-6.430 mIU/mL

Critical value (automatic call-back):  >100 mIU/L

Day(s) Test Performed

Monday - Sunday

Specimen Requirements

Submit only 1 of the following specimens:

Preferred: Plasma

Draw blood in a green-top (lithium heparin) tube(s). For pediatric specimen, draw blood in a green-top (lithium heparin) MICROTAINER(S)®. Label the specimen with the patient’s name (first and last), date of birth, date and time of draw the phlebotomist’s initials and as plasma. Spin down and send 1 mL of lithium heparin plasma refrigerated.

 

Alternate: Serum

Draw blood in a gold-top (serum separator) gel tube. For pediatric specimens, draw blood in two red-top MICROTAINER(S) ®. Label the specimen with the patient’s name (first and last), date of birth, date and time of draw, the phlebotomist’s initials and as serum. Spin down and send 1 mL of serum refrigerated.

 

Specimen stability:   
24 hours at room temperature
2 days refrigerated at 2-8°C
30 days when frozen at ≤ -20°C 

Minimum volume:

1 mL

Specimen rejection criteria:

Moderately hemolyzed specimens are not acceptable.

Test Classification and CPT Coding

84443

Methodology

3rd Generation Chemiluminescent Immunoassay