Amino Acid Profile, Quantitative, Plasma

Methodology: 
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
Performed: 
Monday - Friday
Use: 
This test is used to diagnose and monitor inherited aminoacidurias, organic acidurias and urea cycle defects. It can also be used as a follow-up confirmatory test to some abnormal newborn screen results.
 

Limitations

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.
Specimen Requirements: 
Important: A fasting specimen is preferred to establish baseline values or monitor treatment.
 

Type: Plasma, frozen

Container/Tube: Green-top tube (heparin)
  • Separate plasma or serum from cells. Transfer the specimen to a plastic transport tube before freezing it. Submit separate frozen specimens for each test requested to avoid delays in turnaround time when requesting multiple tests on frozen samples. .

Sample Volume: 0.5 mL

Minimum Volume: 0.25 mL (

Storage: Centrifuge, remove plasma from cells and freeze specimens immediately after collection.

Stability (collection to time of analysis/testing): 
  • Ambient: Unstable
  • Refrigerated: Unstable
  • Frozen: 14 days
Rejection Criteria:
  • Plasma specimen
CPT Code (s): 
82139
Notes: 

UFHPL Test #: 48000

References

  • Bremer HJ, Duran M, Kamerling JP, et al. Disturbances of Amino Acid Metabolism: Clinical Chemistry and Diagnosis. Baltimore, Md: Urban and Schwarzenberg; 1981.
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