Test name: Prolactin
Order Code: PRL
Preferred Specimen: 2mL serum in a Serum Separator Tube (SST or Tiger-top)
CPT Code: 84146
Collection: Allow SST to clot in an upright position for 30 min, then centrifuge sample within 2 hours of collection. Refrigerate.
Special Instructions and Considerations: Samples should not be taken from patients receiving therapy with high biotin doses (i.e. > 5 mg/day) until at least 8 hours following the last biotin administration. When determining prolactin it should be remembered that the measured concentration is dependent upon when the blood sample was taken, since the secretion of prolactin occurs in episodes and is also subject to a 24-hour cycle. The release of prolactin is promoted physiologically by suckling and stress. In addition, elevated serum prolactin concentrations are caused by a number of pharmaceuticals (e.g. dibenzodiazepines, phenothiazine), TRH, and estrogen. The release of prolactin is inhibited by dopamine, L-dopa, and ergotamine derivatives. In case of implausible high prolactin values a precipitation by polyethylene glycol (PEG) is recommended in order to estimate the amount of the biological active monomeric prolactin.
Transport Temperature: Refrigerated
Specimen Stability: 14 days refrigerated