Ordering Recommendations

Aids in the evaluation of Vitamin B12 deficiency

Performed

Tuesday, Thursday

Methodology

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

Reported

Routine: 1 - 5 days

Synonyms

  • Methylmalonate
  • Methylmalonic Acid, Serum
  • MMA, Serum
  • B12 Deficiency
  • Cobalamin Deficiency
  • Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
  • Mass Spectrometry
  • LC/MS/MS
  • Toxicology Laboratory

Performing Lab

CALM Toxicology / Mass Spectrometry

CPT Codes

83921

Add-on Eligibility

Yes, within 7 days of collection

Specimen Type

Blood

Specimen Preparation

Blood specimens collected in Serum Separator Tubes (SSTs) must be centrifuged within 2 hours of the collection time for optimal sample integrity.

NOTE: Specimens collected in SSTs MUST sit for 30 minutes prior to centrifugation to allow for complete clot formation.

Specimen Volume

2.0 mL (Minimum: 1.0 mL)

Collection Container

Serum Separator Tube (SST, Gold Top Vacutainer)

Unacceptable Conditions

  1. Specimens that have been improperly collected, stored, or transported
  • Specimens collected in unacceptable containers
  1. Specimens with insufficient volume for testing
  2. Specimens that have not been centrifuged within 2 hours of collection
  3. Specimens not properly identified per laboratory policy
  • Unlabeled or mislabeled specimens

Storage/Transport Temperature

Transport Instructions    
Collection Location Transport Temperature Processing Required Timeframe
ED/Inpatient Room Temperature None Specimen must be received by the lab within 2 hours of collection
Refrigerated (Ice Packs) Allow blood to clot for 30 minutes in a vertical position. Centrifuge to separate from cells within 2 hours of collection. Specimen must be received by the lab within 7 days of collection
Laboratory/
Outpatient/
Off-Site		 Room Temperature Allow blood to clot for 30 minutes in a vertical position. Centrifuge to separate from cells within 2 hours of collection. Specimen must be received by the lab within 24 hours of collection
Refrigerated (Ice Packs) Allow blood to clot for 30 minutes in a vertical position. Centrifuge to separate from cells within 2 hours of collection. Specimen must be received by the lab within 7 days of collection
Frozen (Dry Ice) Allow blood to clot for 30 minutes in a vertical position. Centrifuge to separate from cells within 2 hours of collection. Specimen must be received by the lab within 1 month of collection

Storage: Refrigerated

Stability (from collection to initiation)

Stability:
Prior to separation from cells:
  • Room Temperature: 2 hours
After separation from cells:
  • Room Temperature: 24 hours
  • Refrigerated: 7 days
  • Frozen at -20°C: 1 month

Laboratory Storage: Frozen
Laboratory Retention: 1 month

Collection Instructions

Labeling Instructions:
  1. When labeling blood tubes, leave a small window visible for the lab to assess the fill volume and sample integrity
  2. Ensure that the barcode is in the correct orientation

Collection Instructions:
  1. Follow the correct order of draw when collecting with additional orders and tube types:
     

Processing Instructions:
  1. Invert the collection tube according to the number of inversions in the chart above
  2. Place the tube upright in a rack and allow the tube to sit for 30 minutes to ensure adequate clotting time
  3. Centrifuge within 2 hours of collection

Reference Interval

0.00 - 0.40 umol/L

Interpretive Data

Methylmalonic Acid Interpretation
Value Interpretation
0.41 - 0.99 umol/L Slight Elevation

Consistent with mild vitamin B12 deficiency, renal insufficiency, or intravascular volume contraction
1.00 - 9.99 umol/L Moderate Elevation

Consistent with mild vitamin B12 deficiency
≥ 10 umol/L Massive Elevation

Consistent with significant vitamin B12 deficiency or with inborn errors of metabolism

Methodology: LC-MS/MS

This test was developed and its performance characteristics determined by the UC San Diego Health Center for Advanced Laboratory Medicine. It has not been cleared or approved by the FDA. The laboratory is regulated under CLIA as qualified to perform high-complexity testing. This test is used for clinical purposes. It should not be regarded as investigational or for research.

Interpretive questions should be directed to Dr. Robert Fitzgerald, Director of the UCSDH Clinical Toxicology Laboratory at 858-657-5733.
Ordering

Ordering Recommendations

Aids in the evaluation of Vitamin B12 deficiency

Performed

Tuesday, Thursday

Methodology

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

Reported

Routine: 1 - 5 days

Synonyms

  • Methylmalonate
  • Methylmalonic Acid, Serum
  • MMA, Serum
  • B12 Deficiency
  • Cobalamin Deficiency
  • Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
  • Mass Spectrometry
  • LC/MS/MS
  • Toxicology Laboratory

Performing Lab

CALM Toxicology / Mass Spectrometry

CPT Codes

83921

Add-on Eligibility

Yes, within 7 days of collection
Collection

Specimen Type

Blood

Specimen Preparation

Blood specimens collected in Serum Separator Tubes (SSTs) must be centrifuged within 2 hours of the collection time for optimal sample integrity.

NOTE: Specimens collected in SSTs MUST sit for 30 minutes prior to centrifugation to allow for complete clot formation.

Specimen Volume

2.0 mL (Minimum: 1.0 mL)

Collection Container

Serum Separator Tube (SST, Gold Top Vacutainer)

Unacceptable Conditions

  1. Specimens that have been improperly collected, stored, or transported
  • Specimens collected in unacceptable containers
  1. Specimens with insufficient volume for testing
  2. Specimens that have not been centrifuged within 2 hours of collection
  3. Specimens not properly identified per laboratory policy
  • Unlabeled or mislabeled specimens

Storage/Transport Temperature

Transport Instructions    
Collection Location Transport Temperature Processing Required Timeframe
ED/Inpatient Room Temperature None Specimen must be received by the lab within 2 hours of collection
Refrigerated (Ice Packs) Allow blood to clot for 30 minutes in a vertical position. Centrifuge to separate from cells within 2 hours of collection. Specimen must be received by the lab within 7 days of collection
Laboratory/
Outpatient/
Off-Site		 Room Temperature Allow blood to clot for 30 minutes in a vertical position. Centrifuge to separate from cells within 2 hours of collection. Specimen must be received by the lab within 24 hours of collection
Refrigerated (Ice Packs) Allow blood to clot for 30 minutes in a vertical position. Centrifuge to separate from cells within 2 hours of collection. Specimen must be received by the lab within 7 days of collection
Frozen (Dry Ice) Allow blood to clot for 30 minutes in a vertical position. Centrifuge to separate from cells within 2 hours of collection. Specimen must be received by the lab within 1 month of collection

Storage: Refrigerated

Stability (from collection to initiation)

Stability:
Prior to separation from cells:
  • Room Temperature: 2 hours
After separation from cells:
  • Room Temperature: 24 hours
  • Refrigerated: 7 days
  • Frozen at -20°C: 1 month

Laboratory Storage: Frozen
Laboratory Retention: 1 month

Collection Instructions

Labeling Instructions:
  1. When labeling blood tubes, leave a small window visible for the lab to assess the fill volume and sample integrity
  2. Ensure that the barcode is in the correct orientation

Collection Instructions:
  1. Follow the correct order of draw when collecting with additional orders and tube types:
     

Processing Instructions:
  1. Invert the collection tube according to the number of inversions in the chart above
  2. Place the tube upright in a rack and allow the tube to sit for 30 minutes to ensure adequate clotting time
  3. Centrifuge within 2 hours of collection
Result Interpretation

Reference Interval

0.00 - 0.40 umol/L

Interpretive Data

Methylmalonic Acid Interpretation
Value Interpretation
0.41 - 0.99 umol/L Slight Elevation

Consistent with mild vitamin B12 deficiency, renal insufficiency, or intravascular volume contraction
1.00 - 9.99 umol/L Moderate Elevation

Consistent with mild vitamin B12 deficiency
≥ 10 umol/L Massive Elevation

Consistent with significant vitamin B12 deficiency or with inborn errors of metabolism

Methodology: LC-MS/MS

This test was developed and its performance characteristics determined by the UC San Diego Health Center for Advanced Laboratory Medicine. It has not been cleared or approved by the FDA. The laboratory is regulated under CLIA as qualified to perform high-complexity testing. This test is used for clinical purposes. It should not be regarded as investigational or for research.

Interpretive questions should be directed to Dr. Robert Fitzgerald, Director of the UCSDH Clinical Toxicology Laboratory at 858-657-5733.

×
Learn More Remind Me Later Dismiss