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Test Code LAB127 Thyroxine, Free (T4F)

Additional Codes

T4F

Collection:

Specimen: Blood 

Preferred: Lt Green w/ Gel - Li Hep

Acceptable: SST or Red Top

Specimen Volume: 5 mL; Minimum 1.0 mL

 

Pediatric Collection:

One Lt Green w/ Gel - Li Hep, SST, or Red Top microtainer filled to 600 uL.

Stability:

If testing is delayed more than 24 hours, remove serum/plasma from the cells or gel separator.  Once serum/plasma is removed from cells or gel separator, specimen is stable for:
 

Ambient: 8 Hours

Refrigerated (preferred): 1 Week

Frozen: 2 Weeks

Turnaround Time (TAT):

STAT: 1 HOUR

Routine: 4 HOURS

Test Availability:

Daily / 24 Hours / Available STAT

Performing Laboratory Section:

Chemistry / UMC MAIN LABORATORY

Reference Interval:

Age Female Male
< 2 months   0.69 - 1.85 ng/dL     0.78 - 1.83 ng/dL  
2 months - < 1 year 0.69 - 1.49 ng/dL 0.71 - 1.56 ng/dL
1 year - < 2 years 0.73 - 1.41 ng/dL 0.82 - 1.32 ng/dL
2 years - < 5 years 0.79 - 1.38 ng/dL 0.80 - 1.32 ng/dL
5 years - < 10 years 0.77 - 1.32 ng/dL 0.78 - 1.29 ng/dL
  10 years - < 15 years   0.66 - 1.22 ng/dL 0.69 - 1.23 ng/dL
15 years - < 19 years 0.67 - 1.22 ng/dL 0.67 - 1.22 ng/dL
> 19 years 0.70 - 1.48 ng/dL 0.70 - 1.48 ng/dL