Skip to Content
UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Tacrolimus

Test Code(s): TAC / HCTAC

CPT Code(s): 80197

Methodology: Immunoassay

Clinical Significance: Immunosuppressive

Days Performed: Daily.

Turnaround Time: Routine: 24 hours.

Specimen Requirements

Specimen: Blood

Patient Preparation: Tacrolimus level should be determined on trough specimen collected just prior to administration of the next dose.

Collection Instructions: Collect specimen just before taking next dose.

Collection Container: Preferred: Lavender top

Collection Volume: Preferred: 4 mL
Pediatrics: 0.2 mL

Specimen Processing: Do NOT centrifuge or separate plasma. SEND WHOLE BLOOD. Refrigerate.

Specimen Transport: Transport specimen at ambient temperature to UWHC Core Laboratory (B4/220).

Stability: Ambient: 14 days
Refrigerated: 14 days
Frozen: 6 months


Interpretive Guidelines:

Definitive therapeutic concentration for tacrolimus (FK506) has not been established. A concentration of 5-15 ng/mL is generally considered to be therapeutic for individuals 18 years old and up.

Critical Calls: View

Additional Information:

The reportable range for tacrolimus is 2-60 ng/mL.  Results of less than 2 ng/mL will be reported as less than 2 ng/mL.


Prograf FK 506 FK506

Back to Lab Test Directory Index