Interference in clinical laboratory testing can create discrepancies in test results which can lead to patient harm.
 In clinical chemistry, interference is defined as a cause of medically significant difference in the measurand test result due to another component or property of the sample.
Interference by endogenous and exogenous substances with assays for clinical analytes is a common problem in laboratory medicine.
 There are four major endogenous compounds that con- sistently interfere with laboratory results: hemoglobin, bilirubin, lipids, and paraproteins.
The major exogenous sources of interference are drugs prescribed for the patient;
We recommend determining whether the interference is dependent or independent of the analyte for the assay. Further, we propose an approach to the identification and resolution of an interference problem for the clinical.