Specimen Requirements

Specimen Type: Plasma or serum

Container/Tube:

Plasma: Lithium heparin, sodium heparin, EDTA, or gel separator

Serum: Clot, plain, activator, or gel separator

Specimen Volume: 0.5 mL

Specimen Minimum Volume: 0.3 mL

Collection Instructions:

1. Trough levels should be drawn 5 minutes before the next dose.

2. Peak levels should be drawn 30 minutes post IV infusion or 1 hour post IM.

Additional Information:

*Grossly hemolyzed or icteric samples are not acceptable.
1. Presence of amikacin, dibekacin, kanamycin B, kanamycin A or neomycin will yield falsely elevated values for tobramycin.
2. High concentrations of β-lactam-type antibiotics (cephalosporins and penicillins) can inactivate tobramycin. Analyze samples immediately from patients receiving these antibiotics in addition to tobramycin or store samples frozen at or below -20Ëš C to prevent tobramycin inactivation in vitro.
3. Heterophilic antibodies in human serum can react with reagent immunoglobulins, interfering with the assay.

Note:  If testing delayed more than 8 hours, remove serum or plasma from the clot, red blood cells, or separator gel.