Development of an ELISA for detection of Sudan I in food samples using monoclonal antibody

A highly sensitive and specific indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) has been developed using a new monoclonal antibody for detecting the food colourant Sudan I. The half-maximum inhibition concentrations (IC₅₀) and the limit of detection (calculated as IC₂₀) of ELISA for Sudan I were 2 and 0.01 ng mL⁻¹, respectively. The study showed little cross-activity with Sudan I structural analogues (below 0.01%). The average recoveries in intra- and interassays for Sudan I from fortified fresh tomato and chilli samples by ELISA were in ranges of 82–94% and 79–91%, respectively. The coefficients of variation of intra- and interassays were 6–8% and 6–10%, respectively. The IC₅₀ was approximately 2.0 ng mL⁻¹ after the Sudan I-Kit had been kept for 180 days.