Home
HelpTest Code T4FDD T 4 Free, Direct Dialysis
Specimen Required
2 mL serum
Specimen Minimum Volume
0.5 mL
Specimen Stability
Room temperature: 7 days Refrigerated: 7 days Frozen: 28 days
Day(s) and Time(s) Performed
Daily a.m.
Method Name
Direct Equilibrium Dialysis • Immunoassay (IA)
Collection Container / Tube
Preferred: Gold SST Tube
Other Acceptable Container: None
Transport Container
Gold Serum Separator Tube
Transport / Storage Conditions
Refrigerated
Special Instructions
Please specify on the request form the patient s age.
Reference Values
Prematures, 25-30 Weeks
Birth-7 Days 0.5-3.3 ng/dL
Prematures, 31-36 Weeks
Birth-7 Days 1.3-4.7 ng/dL
Cord Blood, >37 Weeks 1.2-2.2 ng/dL
Birth-4 Days 2.2-5.3 ng/dL
2 Weeks-2 Years 0.8-2.0 ng/dL
3-20 Years 1.0-2.4 ng/dL
21-87 Years 0.8-2.7 ng/dL
Pregnancy
First Trimester 0.9-2.0 ng/dL
Second Trimester 0.8-1.5 ng/dL
Third Trimester 0.8-1.7 ng/dL
CPT Codes
84439
Analytic Time
Next day
Alias/See Also
LAB13031