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Laboratory Test Directory



Name Method Department Units
Ammonia Enzymatic, reflectometry
Core Lab, Chemistry, Routine umol/L

Specimen Requirements

Plasma Spun

Container Type Container Size Specimen Volume

Green tube (Lithium heparin), with Gel

3 mL 1 mL

Green tube (Lithium heparin), No Gel

3 mL 1 mL

Refrigerated - 3 hour(s)
Frozen - 24 hour(s)

Specimen Preparation

  • Centrifuge, remove plasma/serum and freeze
  • Freeze immediately after collection.

Reasons for Rejection

  • Wrong collection tube
  • Hemolyzed specimen
  • Capillary specimen
  • Specimen not received on ice.
  • Specimen not received within 15 min. of collection


Sample must be received within 15 minutes to insure plasma is removed from cells within 30 minutes. Separated plasma may be stored refrigerated but must be analyzed within 3 hours. Frozen plasma is stable up to 24 hours. Capillary collection (heel, finger stick) is NOT acceptable.

CPT Code

  • 82140