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.
Note:  1. When determining prolactin, it should be noted that measured concentration is dependent upon when blood specimen is drawn, since secretion of prolactin occurs in episodes and is also subject to a 24-hour cycle. Prolactin levels are lowest a few hours after waking. Draw blood in a.m., assuming normal waking hours. Prolactin is a stress hormone, and stressors may cause a transient rise.

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

3. Heterophile antibodies may interfere with this assay.

4. Indicate serum on request form.

5. Label specimen appropriately (serum).

Alternate: 

Plasma

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

Note:  1. When determining prolactin, it should be noted that measured concentration is dependent upon when blood specimen is drawn, since secretion of prolactin occurs in episodes and is also subject to a 24-hour cycle. Prolactin levels are lowest a few hours after waking. Draw blood in a.m., assuming normal waking hours. Prolactin is a stress hormone, and stressors may cause a transient rise.

2. Heterophile antibodies may interfere with this assay.

3. Indicate plasma on request form.

4. Label specimen appropriately (plasma).

Specimen Stability Information