Specimen

Plasma

Collection Medium:

Minimum:

Preferred minimum: 4 mL heparinized plasma in a green-top (heparin) 
tube from a fasting patient (4 hours or more in infants).
Absolute miniumum: 0.5 mL heparinized plasma

Rejection Criteria:

Thrombin-activated tube is not acceptable.

Analytic Time:

3 working days

Reference Range:

Age-dependent reference values are listed under "Inborn Errors of Amino 
Acid Metabolism" in Special Instructions, by report.

Comments:

Patient's age is required on request form for processing. Include 
family history, clinical condition (asymptomatic or acute episode), 
diet, and drug therapy information.

Test
Limitations:

Biochemical test results depend in part on the clinical and dietary 
status at the time of specimen collection.  A normal or non-diagnostic 
test result does not rule out the possibility of an underlying 
metabolic disorder, including that for which the test was requested.

Methodology:

Ion-Exchange Chromatography, Quantitative
Includes quantitation of the following amino acids: taurine, threonine, 
serine, asparagine, glutamic acid, glutamine, proline, glycine, 
alanine, citrulline, a-aminoadipic acid, a-amino-N-butyric acid, 
valine, cystine, cystathionine, methionine, isoleucine, leucine, 
tyrosine, phenylalanine, b-alanine, b-aminoisobutyric acid, ornithine, 
lysine, 1-methylhistidine, histidine, 3-methylhistidine, carnosine, and 
arginine.

CPT Code:

82139

See Additional Information:
Fasting Specimen Requirements