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Order Code MMAP Methylmalonic Acid, Quantitative, Plasma

Reporting Name

Methylmalonic Acid, QN, P

Useful For

Evaluating children with signs and symptoms of methylmalonic acidemia using plasma specimens

 

Evaluating individuals with signs and symptoms associated with a variety of causes of vitamin B12 (cobalamin) deficiency

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Plasma


Specimen Required


Collection Container/Tube:

Preferred: Green top (sodium heparin)

Acceptable: Lavender top (EDTA)

Submission Container/Tube: Plastic vial

Specimen Volume: 1.5 mL

Collection Instructions: Centrifuge and aliquot plasma into a plastic vial.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Plasma Refrigerated (preferred) 48 days
  Ambient  48 days
  Frozen  48 days

Reference Values

≤0.40 nmol/mL

Day(s) Performed

Monday through Friday

CPT Code Information

83921

Method Description

Methylmalonic acid (MMA) is determined by liquid chromatography tandem mass spectrometry (LC-MS/MS) stable isotope dilution analysis. The specimen is mixed with an internal standard (methyl-d3-malonic acid). MMA and d3-MMA are isolated by solid phase extraction. LC-MS/MS is performed using mobile phases and a short column (C18, 50 mm x 4.6 mm, 5 microns) to separate MMA and d3-MMA from the bulk of the specimen matrix. The MS/MS is operated in the multiple reaction monitoring (MRM) negative mode to follow the precursor to product species transitions. Separation of MMA/d3-MMA from the more physiologically abundant succinic acid is accomplished by the careful selection of MRM transitions and optimization of the LC separation. The ratios of the extracted peak areas of MMA to d3-MMA determined by LC-MS/MS are used to calculate the concentration of MMA present in the sample.(Unpublished Mayo method)

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Benign Hematology Test Request (T755)

-Biochemical Genetics Test Request (T798)