Within the sample matrix itself exists components that occur pre-analytically that may affect the accurate analysis of the intended measurand.
Triglycerides and chylomicrons
Protein and immunoglobulins
For many analytes, interferent studies have been performed by the manufacturer of the assay or analytical reagents to test the effects of these matrix interferents at various concentrations of the interfering substances. For laboratory-developed tests, or tests for which such interference studies are not available, the laboratory should perform interference testing in accordance with the CLSI recommendations.