**Conclusion** *Glucose reagent interferes with TBil estimation *Probably there is reagent carry over. *Introduce one Deteregent wash cycle in between Glucose (interfering test) and Tbil (Interfered Test) in ERBA 640 XL. *Documentation for introducing Wash Cycle *{{:nchsls:c:biochemistry:document:total_bilirubin_and_glucose_carryover_.ods|}} **Mechanism** *H2O2 produced by GOD POD reaction destroys bilirubin. *So Bilirubin was low in result. One wash cycle was set inbetween two tests to eliminate carry over.