Specimen Requirements

Plasma

Draw blood in a green-top (lithium heparin) tube. Label the specimen with the patient’s name (first and last), date of birth, date and time of draw and the phlebotomist’s initials. Spin down and send 1 mL of lithium heparin plasma refrigerated. 

Trough level should be drawn just prior to next dose.

Specimen stability:

8 hours at room temperature

2 days refrigerated at 2-8°C

30 days when frozen at ≤ -20°C 

Minimum volume:    
1 mL