Specimen Requirements

Due to interference, patients receiving high doses of biotin (>5 mg/day) should wait at least 8 hours after dose before having blood drawn.

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.
Note:

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

2. Draw specimen before biopsy, prostatectomy, or prostate massage since manipulation of prostate may lead to elevated PSA levels persisting up to 3 weeks.

3. Patients receiving therapy with mouse monoclonal antibodies may have erroneous results.

4. Indicate serum on request form.

5. Label specimen appropriately (serum).

Alternate: Preferred by Siemens Users

Plasma

Draw blood in a mint green-top (lithium heparin) gel tube(s) or a lavender-top (EDTA) tube(s). Spin down and send 1 mL of heparinized or EDTA plasma refrigerated.

Note:  1. Draw specimen before biopsy, prostatectomy, or prostate massage since manipulation of prostate may lead to elevated PSA levels persisting up to 3 weeks.

2. Patients receiving therapy with mouse monoclonal antibodies may have erroneous results.

3. Indicate plasma on request form.

4. Label specimen appropriately (plasma).

Specimen Stability Information