Method(s): LC-MS/MS (1).
What is measured: Total choline esters (as opposed to free choline), after liberation of choline from phospholipids (mainly phosphatidylcholine) in the presence of phospholipase D (PLD) and calcium.
The concentrations of the other metabolites in serum/plasma obtained from platform C are not affected by PLD treatment, and are simultaneously measured by this modified assay.

What is measured on the same platform, click here.
Platform C: Chol, (tChol), TMAO, Bet, DMG, tHcy, Creat, Crn, Met, MetSo, Cysta, tCys, His, 3-MH, 1-MH, Cit, Orn, Arg, ADMA, SDMA, hArg, TML

Performance of the assay

Lower limit of detection (LOD): 1 µmol/L.
Within-day CV: 3 %; between-day CV: 4 %.


Assessment of of one-carbon status. Choline deficiency.

Specimen, collection and processing

Patient/subject: Prandial status affects the concentration, which increases after a meal. The subjects should be fasting.
Matrix: Serum or plasma. Total choline concentration (as opposed to the concentration of free choline) is not affected by the preanalytical conversion of phospholipids to free choline in serum.
Volume: Minimum volume is 50 µL, but 200 µL is optimal and allows reanalysis.
Preparation and stability: Stable in frozen stored serum/plasma for years.

Transportation; for general instruction on transportation, click here.

Frozen, on dry ice.

Reported values, interpretation

Reported values: 2-3 mmol/L.
Intraclass correlation coefficient (ICC): na.


1. Midttun, O., Kvalheim, G., and Ueland, P.M. (2013). High-throughput, low-volume, multianalyte quantification of plasma metabolites related to one-carbon metabolism using HPLC-MS/MS. Anal Bioanal Chem 405, 2009-017