Specimen Requirements

Submit only 1 of the following specimens:

Plasma
Draw blood in a green-top (lithium heparin) tube from a fasting patient. (Hemolyzed specimen is not acceptable.) Spin down and send 2 mL of lithium heparin plasma.

Note: 1. Indicate plasma.

2. Label specimen appropriately (plasma).

Serum
Draw blood in a gold-top serum gel tube from a fasting patient. (Hemolyzed specimen is not acceptable.) Spin down and send 2 mL of serum.

Note: 1. Indicate serum.

2. Label specimen appropriately (serum).

Specimen for a trough level is usually drawn 30 minutes before dose.