Metanephrines, Plasma (Free) METPL
|Method(s)||High Performance Liquid Chromatography|
Two 3 mL lavender (EDTA) cap tubes. Also acceptable: One pink (K2EDTA) cap tube.
2 mL plasma, frozen. (Min: 1 mL) CRITICAL FROZEN.
CRITICAL FROZEN. Centrifuge within 1 hour of collection. Remove plasma from cells and freeze immediately.
|Stability||After separation from cells: Ambient: Unacceptable; Refrigerated: Unacceptable; Frozen: 1 month|
Plasma separator tubes, body fluids other than EDTA or heparinized plasma; non-frozen specimens.
Patient Preparation: Drugs and medications may affect results and should be discontinued for at least 72 hours prior to specimen collection, if possible. Collection of the specimen after the patient has rested for 15 minutes in a supine position is recommended. Isoetharine, isoproterenol, 3, 4-methylenedioxyamphetamine (MDA), and 3, 4-methylenedioxymethamphetamine (MDMA) are known to interfere in this test.
|Preferred Specimen Collection Device(s)|
Normetanephrine: 0.0-0.89 nmol/L