Method(s): GC-MS/MS (1).
What is sarcosine?
Sarcosine is formed from dimethylglycine (dimethylglycine dehydrogenase) or by methylation of glycine (glycine-N-methyl transferase). It is degraded to glycine (sarcosine dehydrogenase).
Performance of the assay
Lower limit of detection (LOD): na.
Within-day CV: 5 %; between-day CV: na.
Assessment of choline and one-carbon status.
Specimen, collection and processing
Patient/subject: No special precaution.
Matrix: Sarcosine cannot be determined in samples collected into EDTA Vacutainer Tubes from some producer(s) (Becton, Dickinson), because of the presence of significant amounts of sarcosine in such tubes.
Volume: Minimum volume is 50 µL, but 200 µL is optimal and allows reanalysis.
Preparation and stability: The blood sample must be centrifuged and the plasma/serum fraction put on ice, and frozen.
Transportation; for general instruction on transportation, click here.
Frozen, on dry ice.
Reported values, interpretation
Reported values: 0.7-2.3 µmol/L
Intraclass correlation coefficient (ICC): 0.68.
1. Midttun, Ø., McCann, A., Aarseth, O., Krokeide, M., Kvalheim, G., Meyer, K., and Ueland, P.M. (2016). Combined measurement of 6 fat-soluble vitamins and 26 water-soluble functional vitamin markers and amino acids in 50 μL of serum or plasma by high-throughput mass spectrometry. Anal Chem 88, 10427-436.