Test ID BDSP0023 Allo-isoleucine, Blood Spot
Useful For
Evaluation of newborn screening specimens that test positive for branched-chain amino acids elevations
Follow-up of patients with maple syrup urine disease
Special Instructions
Specimen Type
Whole bloodSpecimen Required
Supplies: Card - Blood Spot Collection (Filter Paper) (T493)
Container/Tube:
Preferred: Blood Spot Collection (Filter Paper)
Acceptable: Local newborn screening card, Whatman Protein Saver 903 filter paper, PerkinElmer 226filter paper, Munktell filter paper, Postmortem Screening Card
Specimen Volume: 2 Blood spots
Collection Instructions:
1. Do not use device or capillary tube containing EDTA to collect specimen.
2. At least 1 spot should be complete and unpunched.
3. An alternative blood collection option for a patient older than 1 year is a fingerstick. For detailed instructions, see How to Collect Dried Blood Spot Samples.
4. Include type of feeding information on the collection card.
5. Let blood dry on filter paper at ambient temperature in a horizontal position for a minimum of 3 hours.
6. Do not expose specimen to heat or direct sunlight.
7. Do not stack wet specimens.
8. Keep specimen dry.
Additional Information:
1. For collection instructions see Blood Spot Collection Instructions.
2. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777).
3. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800).
Specimen Minimum Volume
1 Blood spot
Reject Due To
Blood spot shows layering Serum rings Multiple applications Insufficient specimen |
Reject |
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole blood | Ambient (preferred) | 59 days | FILTER PAPER |
Frozen | 59 days | FILTER PAPER | |
Refrigerated | 59 days | FILTER PAPER |
Day(s) Performed
Monday through Friday
Report Available
2 to 4 daysMethod Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Portions of this test are covered by patents held by Quest Diagnostics
Performing Laboratory
Mayo Clinic Laboratories in RochesterCPT Code Information
82136
Secondary ID
88888Reporting Name
Allo-isoleucine, BSReference Values
Allo-isoleucine: <2 nmol/mL
Leucine: 35-215 nmol/mL
Isoleucine: 13-130 nmol/mL
Valine: 51-325 nmol/mL
An interpretive report will also be provided.
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.Forms
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.