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Test Code SQ TAC, EPIC LAB5403 Tacrolimus (FK 506), Blood


Liquid Chromatography/Mass Spectrometry (LC/MS)

Performing Laboratory

University of Wisconsin Hospital and Clinics

Specimen Requirements

Specimen Type: Whole blood
Container/Tube: Lavender top (EDTA)
Specimen Volume: 4 mL

Specimen Absolute Minimum Volume: 0.5 mL

Collection Instructions:

1. Draw blood just prior to next dose.

2. Do NOT open or centrifuge tube.

Specimen Transport Temperature

Ambient preferred

Refrigerated OK

Frozen NO

Reference Values

Definitive therapeutic concentration for tacrolimus has not been established. A concentration of 5 to 15 ng/mL is generally considered to be therapeutic for individuals ≥18 years.

Note: The reportable range for tacrolimus is 1 to 80 ng/mL. Results <1 ng/mL will be reported as <1 ng/mL.

Day(s) Test Set Up

Monday through Sunday

Pathology resident approval is required after hours.

Analytical Time




1 day

Test Classification and CPT Coding