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TOBRAMYCIN, serum (087-8115)
Test Mnemonic:

TOBRA T (trough), TOBRA P (peak), TOBRA R (random)

Specimen Requirements:

Routine venipuncture. Peak: Collect 0.5-1.0 hours after the end of a 30-minute infusion or 1 hour after IM dose. Trough levels are drawn immediately before dosing.  7 mL of blood in Red-topped tube. Do not use SST/serum separator tubes. (Min.: 3 mL of blood).

DO NOT draw blood in SST/gel separator vacutainer tube.


Delivered to Sample Management within 2 hours of collection.  

Specimen Preparation:

Allow specimen to clot completely at room temperature. Centrifuge to separate serum from cells within 2 hours of collection. Transfer serum from red-topped tube to labeled plastic transport tube. 


Room Temperature for ≤2 hours, Refrigerated   for ≤7 days, Frozen for ≤14 days. (Avoid repeated freeze/thaw cycles).

Causes for Rejection:

Blood drawn in SST/gel separator vacutainer tube, incomplete and/or incorrect sample identification, improper storage/transport, gross hemolysis, icterus or lipemia.                                                                                                       

Reference Range:

By report (reports may vary based on instrumentation, patient age and sex)

Turnaround Time:

Routine: 8 hours; ASAP: 4 hours; STAT: 1 hour




Clinical Chemistry

CPT 4 Code:



If the sample is obtained through the infusion set, flush the line thoroughly with saline before taking the blood sample. Indicate additional antibiotic therapy on the request slip.

When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient. Components of the organ or disease panels may be ordered individually. The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-10 code or its verbal equivalent.
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