Red serum vial/tube - 5 mL

Trough levels are most reproducible

1. Allow sample to clot
2. Spin
3. Transfer serum to a Serum/plasma transfer vial/tube (MedTox), labelled as serum, within two (2) hours of sample collection

Serum/plasma transfer vial/tube (MedTox)

Dk green heparin (Li or Na), no gel

Immediatley following collection, mix sample thoroughly by gentle inverting 8 - 10 times, to prevent clotting

1. Spin
2. Transfer plasma to a Serum/plasma transfer vial/tube (MedTox), labelled as the appropriate plasma type, within two (2) hours of sample collection

Refrigerated (preferred) - 14 days

Ambient - 3 days

Frozen - 180 days

• Gel barrier tubes

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

Expected  in patients taking recommended dosages: up to 60.0 µg/mL