Organic Acid Disorders by Tandem Mass Spectrometry (MSMS)

Method Extraction of dried blood spots with a solution containing stable-isotope labeled internal standards and analysis using MSMS.
CPT Code 83789
Testing Scope Detection of low or elevated free carnitine and acylcarnitines from clinical specimens.
Preferred Specimen Heel stick dried blood spots collected on FDA-approved filter paper (Perkin Elmer 226 Ahlstrom) at 24-48 hours of age and at 10-14 days of age.
Specimen Container Specimen collection kit comes with a biohazard flap to cover the blood when dried for about 4 hours and placed in an envelope for shipment.
Specimen Identification All information fields on the kit must be completely filled out. Each kit has a unique serial number and barcode.
Special Instructions After air-drying for 4 hours, send specimen for overnight delivery within 24 hours after collection.
Shipping Requirements Do not place specimen in a zipper bag without desiccant.
Do not expose to direct sunlight, excessive humidity or high temperature.
Note Blood transfusion may interfere with the assay.
Sample Rejection Criteria
  • Quantity not sufficient (QNS)
  • Not evenly saturated
  • Diluted/Discolored/Contaminated
  • Repetitive/Overlapping Blood Spots
  • Clotted/Layered/Oversaturated
  • Damaged
  • Separated/Serum Rings
  • Too Old (>14 days from collection)
Turnaround Time Normal result within 24-36 hours.
Presumptive positive result within 48-72 hours.