Test Directory

Diagnosis and monitoring of inherited aminoacidurias, organic acidurias, and urea cycle defects. May be used as a follow-up confirmatory test to some abnormal newborn screen results.

Specimen Type: Plasma

Preferred Collection Container: Green Top (Sodium Heparin)

Alternate Collection Container: Green Top (Lithium Heparin), Lavender (EDTA), or White Top (EDTA)  

Desired Specimen Volume: 0.5 mL

1. Collection green top, sodium heparin tube via venipuncture

1. Separate plasma from cells.
2. Transfer 0.5 mL of plasma to a LabCorp transpak frozen purple tube and freeze immediately.
3. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.

Transport to the laboratory frozen. 

• Gross hemolysis
• Room temperature or thawed specimens
• Specimens collected in yellow-top (ACD) tubes

 See patient report.

False-negative results can occur, especially when a patient is affected with a mild or intermittent variant of a disorder or when clinical condition or dietary treatment causes secondary changes to the profile. Results of amino acid profiling should be interpreted in the context of clinical presentation, as well as other laboratory tests. Frozen serum may be diagnostic, however, certain amino acids may be falsely elevated or low.