Sign in →

Test Code TACPK Tacrolimus, Peak, Blood

Necessary Information

Date of last dose, time of last dose, and dosage information are required.

Specimen Required

Container/Tube: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions: 

1. Do not centrifuge.

2. Send specimen in original tube.

Useful For

Assessment of postdosing (peak) blood tacrolimus concentrations

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Tacrolimus, Peak, B

Specimen Type

Whole Blood EDTA

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Whole Blood EDTA Refrigerated (preferred) 14 days
  Ambient  14 days
  Frozen  14 days

Reject Due To


Mild OK; Gross OK


Mild OK; Gross OK


Mild OK; Gross OK



Reference Values

5.0-30.0 ng/mL


Target steady-state trough concentrations vary depending on the type of transplant, concomitant immunosuppression, clinical/institutional protocols, and time posttransplant. Results should be interpreted in conjunction with this clinical information and any physical signs or symptoms of rejection or toxicity.

Day(s) and Time(s) Performed

Monday through Friday; Continuous until 3 p.m.

Saturday, Sunday; Continuous until 1 p.m.

Analytic Time

Same day/1 day

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
TACPK Tacrolimus, Peak, B 59822-7


Result ID Test Result Name Result LOINC Value
88157 Tacrolimus, Peak, B 59822-7
DAT7 Date of last dose 29742-4
TM01 Time of last dose 29637-6
DOSE1 Dose, mg 32594-4