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Epic Code LAB126 T4 (Thyroxine), Total, Blood Level

Important Note

Method is Roche cobas Electrochemiluminescense Immunoassay.
Patient results determined by assays using different manufacturers for methods may not be comparable.

Test Name Alias

T4 Total | 724

Interface Order Alias

11084

Ordering Instructions

Please keep in mind, biochemical thyroid function evaluation should begin with the Thyroid Function Cascade (SH#6701)

Collection Instructions

Specimen Collection: Blood

 

Container(s): 4.5 mL Mint Green Top (Lithium Heparin Gel) or 5.0 mL Gold Top (Serum Separator-SST Gel)

Preferred Volume to Collect: 4.5 mL

Minimum Volume to Collect: 1.0 mL

Neonate Volume to Collect: 0.5 mL

Capillary collect ok? Yes

Microtainer acceptable: Yes

 

Collection Instructions:

  • After collection, gently invert tube 8-10 times.
  • Specimen should be processed within 2 hours – See Processing Instructions.

 

Processing Instructions (Laboratory, Outpatient or Off-site collection)

 

Processed Specimen: Plasma or Serum

Centrifuge/Spin: Yes

Aliquot: Yes

 

Processing Instructions:

  • Plasma is preferred specimen type
  • Green Tube/Plasma: Centrifuge after collection.
  • Gold Tube/Serum: Allow blood to clot for 30 minutes in a vertical position and centrifuge within 2 hours.

Transport Temperature: Refrigerate

Specimen Stability

Ambient: 8 hours

Refrigerate: 72 hours

Frozen: aliquot plasma/serum for longer storage

Laboratory Retention: 72 hours

Test Frequency

Available daily, usual TAT 1 day.

Reference Range

4.5 to 11.7 mcg/dL

Performing Department

Chemistry

Performing Department Laboratory Location

Corewell Health Reference Laboratory, Grand Rapids, MI

Methodology

Method is Roche cobas Electrochemiluminescense Immunoassay.
Patient results determined by assays using different manufacturers for methods may not be comparable.

CPT

84436

CDM Code

3018443602

Epic Test ID

1230101198

LOINC

Total T4: 3026-2

Mayo Access Code

SHO724

Reviewed Date

3/7/2024