Expected Turnaround Time
3 - 6 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Information
Related Documents
Specimen Requirements
Specimen
Plasma, frozen
Volume
0.5 mL
Minimum Volume
0.15 mL (Note: This volume does not allow for repeat testing.)
Container
Preferred: Frozen plasma from green-top (sodium heparin) tube. Acceptable: Frozen plasma from green-top (lithium heparin) tube, frozen plasma from lavender-top (EDTA) tube or frozen plasma from PPT™. Frozen serum from serum separator tube (SST) or frozen serum from red-top tube will not be rejected. Note: Plasma reference ranges will be applied to all specimen types.
Collection
Separate plasma from cells. Transfer specimen to plastic transport tube before freezing. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Storage Instructions
Centrifuge, remove plasma from cells, and freeze immediately.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | Unstable |
Refrigerated | Unstable |
Frozen | 14 days |
Causes for Rejection
Gross hemolysis; room temperature or thawed specimen; specimens collected in yellow-top (ACD) tubes
Test Details
Use
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.
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. Frozen serum may be diagnostic, however, certain amino acids may be falsely elevated or low.
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Methodology
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
Reference Interval
See Plasma Amino Acid Reference Intervals in the Test Resources pages online.
References
Bremer HJ, Duran M, Kamerling JP, et al. Disturbances of Amino Acid Metabolism: Clinical Chemistry and Diagnosis. Baltimore, Md: Urban and Schwarzenberg; 1981.
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700007 | Taurine | umol/L | 20657-3 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700008 | Aspartate | umol/L | 20639-1 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700009 | Hydroxyproline | umol/L | 20647-4 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700010 | Threonine | umol/L | 20658-1 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700011 | Serine | umol/L | 20656-5 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700012 | Asparagine | umol/L | 20638-3 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700014 | Glutamate | umol/L | 20642-5 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700015 | Glutamine | umol/L | 20643-3 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700016 | Sarcosine | umol/L | 26613-0 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700017 | Alpha-aminoadipate | umol/L | 26600-7 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700018 | Proline | umol/L | 20655-7 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700019 | Glycine | umol/L | 20644-1 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700020 | Alanine | umol/L | 20636-7 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700022 | Citrulline | umol/L | 20640-9 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700023 | Alpha-aminobutyrate | umol/L | 20634-2 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700024 | Valine | umol/L | 20661-5 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700025 | Cystine | umol/L | 22672-0 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700026 | Methionine | umol/L | 20651-6 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700027 | Homocitrulline | umol/L | 55876-7 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700028 | Cystathionine | umol/L | 26607-2 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700029 | Alloisoleucine | umol/L | 22670-4 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700030 | Isoleucine | umol/L | 20648-2 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700031 | Leucine | umol/L | 20649-0 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700032 | Tyrosine | umol/L | 20660-7 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700033 | Phenylalanine | umol/L | 14875-9 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700034 | Argininosuccinate | umol/L | 32227-1 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700035 | Beta-alanine | umol/L | 26604-9 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700036 | Beta-aminoisobutyrate | umol/L | 26605-6 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700037 | Homocystine | umol/L | 20646-6 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700038 | Gamma-aminobutyrate | umol/L | 26609-8 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700040 | Tryptophan | umol/L | 20659-9 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700041 | Hydroxylysine | umol/L | 26610-6 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700042 | Ornithine | umol/L | 20652-4 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700043 | Lysine | umol/L | 20650-8 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700044 | Histidine | umol/L | 20645-8 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700045 | Arginine | umol/L | 20637-5 |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700063 | Interpretation | 49247-0 | |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700064 | Director Review | 72486-4 | |
| 700068 | Amino Acid Profile, Qn, Plasma | 35083-5 | 700065 | Methodology | 49549-9 |
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