Method(s): GC-MS/MS (1).
Performance of the assay (GC-MS/MS)
Lower limit of detection (LOD): 3 µmol/L.
Within-day CV: 1 %; between-day CV: 3 %.
Assessment of one-carbon status.
Specimen, collection and processing
Patient/subject: Prandial status affects concentration, which increases slightly after a protein rich meal..
Matrix: Serum or EDTA plasma. The concentration is about 25 % higher in serum than in plasma.
Volume: Minimum volume is 50 µL, but 200 µL is optimal and allows reanalysis.
Preparation and stability: There is a time-dependent increase in glycine in serum.
Transportation; for general instruction on transportation, click here.
Frozen, on dry ice.
Reported values, interpretation
Reported values: 150-300 µmol/L.
Intraclass correlation coefficient (ICC): 0.81.
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.