Specimen Requirements

Collection Instructions:

1. Serum and Plasma gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged and aliquoted within 2 hours of collection.

Submit only 1 of the following specimens:

Preferred:

Serum

Draw blood in a gold-top serum gel tube(s). Spin down and send 1 mL of serum refrigerated. Specimen is usually drawn 2 hours post infusion or 15 minutes before dose for intravenous piggyback (IVPB) or intravenous push (IVP). For an oral dose, specimen is drawn immediately prior to next dose.

Note:

1. Patients receiving fosphenytoin should wait at least 2 hours after an intravenous administration and 4 hours after an intramuscular administration before having blood drawn.

2. Date and time of draw is required on request form and specimen for processing.

3. A speckled-top serum gel tube (s) or a plain, red-top tube(s) is also acceptable.

4. Indicate serum and if draw is pre- or post-dose on request form.
5. Label specimen appropriately (serum and as pre- or post-dose).

Alternate (Preferred for VWH Lab): 

Plasma

Draw blood in a mint green-top (heparin) gel tube(s). Spin down and send 1 mL of heparinized plasma refrigerated. Specimen is usually drawn 2 hours post infusion or 15 minutes before dose for intravenous piggyback (IVPB) or intravenous push (IVP). For an oral dose, specimen is drawn immediately prior to next dose.

Note: 

1. Patients receiving fosphenytoin should wait at least 2 hours after an intravenous administration and 4 hours after an intramuscular administration before having blood drawn.

2. Date and time of draw is required on request form and specimen for processing.

3. Indicate plasma and if draw is pre- or post-dose on request form.
4. Label specimen appropriately (plasma and as pre- or post-dose).

VWH Lab: 

5. Tubes of blood are to be kept closed at all times and in a vertical position. It is recommended that the serum or plasma be physically separated from contact with cells within two hours from the time of collection.

6. Separated serum or plasma should not remain at room temperature longer than 8 hours. If assays are not completed within 8 hours, serum or plasma should be stored at +2°C to +8°C for up to 48 hrs. 

Roche Specimen Stability Information