The amount of a 1-O-alpha-D-Glucopyranosyl-1,2-nonadecandiol when measured in blood serum. The trait is level of 1-O-alpha-D-Glucopyranosyl-1,2-nonadecandiol in blood serum (Ontology of Biological Attributes term OBA_2045041). Also known as: blood serum 1-O-alpha-D-Glucopyranosyl-1,2-nonadecandiol amount.