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Organic Acid Analysis |
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Biochemical Genetics
Laboratory Organic Acid Analysis
INDICATIONS FOR TESTING:
Organic acid analysis of urine is indicated in
infants presenting with acidosis with an anion gap, seizures, lethargy,
developmental delay and failure to thrive. Combined with a serum amino acid
screen, these tests provide a comprehensive screen for disorders of intermediate
metabolism.
METHODOLOGY:
Analysis is performed by Gas Chromatography and Mass
Spectrometry (GC/MS). Samples are converted to oxime derivatives prior to
extraction by organic solvent. The dried extract is derivatized with
trimethylsilyl (TMS) reagent. The TMS derivatives are separated by capillary gas
chromatography and detected by Electron Ionization Mass Spectrometry. All
significant components are checked against reference libraries for positive
identification. Relative amounts are compared to an internal standard. This is a
screening method and accurate quantitation of the organic acids with this method
is not reliable. The overall pattern is evaluated and compared with patterns
obtained from patients with verified inborn errors of metabolism and normal
controls.
TURN-AROUND TIME:
Organic Acid analysis is completed within a time of 3
working days following specimen receipt. Samples are batched. One-day
turn-around time is offered on acutely ill infants with a strong suspicion of a
metabolic disorder.
SPECIMEN REQUIREMENTS:
Urine:
- Preferred Volume = 5.0 mL
- Absolute minimum = 2.0 mL
Collection Notes:
- A 24-hour collection is preferred but random
collections are accepted.
- Avoid using soaps when using collection bags.
- Do not use preservatives (especially strong acids).
Shipping and Handling:
- Optimal: Ship
frozen with dry ice in an insulated container
- Acceptable: Ship thawed with cool pack in an
insulated container
- Use overnight delivery if available.
CPT CODES:
- Organic Acid Screen: 83919
FOR MORE INFORMATION, PLEASE
CONTACT:
Phone:
(727) 767-8689 (Laboratory)
Fax: (727) 767-8514
E-mail:
benfords@allkids.org
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