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Test 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

Message

Please specify on the request form the patient s age.