blood intermediate-density lipoprotein phospholipid measurement test serum intermediate-density lipoprotein phospholipid measurement test 2014-01-15T13:07:54Z A laboratory test which measures the amount of phospholipid (phosphorus-containing lipids composed mainly of fatty acids, a phosphate group, and a simple organic molecule) found in the intermediate-density lipoprotein (IDL) fraction of serum, the clear liquid that separates from blood after it has clotted completely, i.e. blood plasma from which fibrinogen has been removed. IDL are relatively large lipoprotein particles (complexes that consist of a protein layer surrounding a core of lipids) formed by degredation of very low density lipoproteins (VLDL) particles and thus having a size intermediate between those of VLDL and low density lipoproteins (diameter approximately 25-50 nm). JSmith MMO:0000483 measurement_method_ontology serum IDL phospholipid test