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Test Code T4F FREE T4  

Additional Codes

N.FREET4

Methodology

Automated Chemistry Analyzer

Specimen Requirements

Serum

Container: Serum or Green top Lithium heparin

Specimen Collection: 1 mL (minimum 0.5 mL)

  1. Allow specimen to clot completely if  a serum tube (SST) was used. Separate serum (SST) or plasma (Lithium Heparin) from cells within 24 hours and transport refrigerated. If red top tube is collected, separate serum from cells within 2 hours and place in separate plastic tube.
  2. Properly label tube with patients name, DOB, requisition number and type of tube, i.e. GREEN.

 

Specimen Transport/Stability

Refrigerated: 24 hours on gel, 6 days poured off

Maximum Laboratory Time

24 to 48 hours

Reference Ranges

Free T4          ng/dL  
Newborn      0.70 - 2.20
18 yrs      0.70 - 1.48

 

Day(s) Test Set Up

Daily

Test Classification and CPT Coding

84439