Interferentskatseid

Interferentskatseid, often translated as interference test, is a method used to assess how potential interfering substances affect the accuracy of a measurement method or assay. The test is commonly employed in analytical chemistry, clinical laboratory science, and immunoassay development to identify substances that could bias results.

Procedure typically involves establishing a baseline measurement with a control sample, then fortifying parallel samples with candidate interferents at concentrations representative of real-world conditions. The same assay is performed on both sets, and interference is quantified as the difference or percent bias between fortified and control results. Acceptance criteria are defined in method validation plans and guided by standards from bodies such as the CLSI or IFCC. If interference exceeds predefined thresholds, mitigation strategies—such as alternative assays, dilution, or pretreatment—may be pursued.

Common interferents include endogenous substances such as bilirubin (icterus), lipids (lipemia), and hemoglobin (hemolysis); exogenous substances such as drugs or metabolites; and assay-specific factors like heterophilic antibodies in immunoassays. The specific list and concentrations tested depend on the intended clinical or analytical use.

Applications include method validation, assay development, quality control, and regulatory submissions, ensuring reliable results across diverse patient populations. Limitations include the impracticality of testing every possible interferent, the dependence of interference on the particular assay design, and the need to interpret results in a clinical context.