False positive or false negative results in immunoassay are caused by the interference of antibody, detection substance, detection carrier surface and detection substance in the detection sample. Blockers are a class of bioactive preparations used in in vitro diagnostic detection experiments to eliminate or reduce the interference of immunoassay. The application of blockers in in vitro diagnostic tests can effectively reduce the false positive or false negative results caused by immunoassay interference. In the process of using in vitro diagnostic reagents, they are susceptible to interference by endogenous antibodies or other binding immunoglobulins in patient samples. The detection susceptible to interference mainly includes double antibody sandwich detection, competitive detection and lgM capture detection. Heterophile Antibody (HA), Rheumatoid Factors (RF) and Human Anti-Animal Antibody (HAAA) are the main known interferors