Production of the monoclonal antibody against Sudan 4 for multi-immunoassay of Sudan dyes in egg

• Published in: Food control Vol. 27; no. 1; pp. 146 - 152
• Main Authors: Shan, Wen Chong, Xi, Jian Zhong, Sun, Jie, Zhang, Yu Jie, Wang, Jian Ping
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2012
• Subjects: Egg; Heterologous immunoassay; Monoclonal antibody; Sudan 4; Sudan dyes; Sudan 4; Sudan dyes; Monoclonal antibody; Egg; Heterologous immunoassay
• ISSN: 0956-7135; 1873-7129
• DOI: 10.1016/j.foodcont.2012.03.017

Sudan dyes (Sudan 1, 2, 3, 4, Para red and Sudan red G) have been banned as food colorants due to their carcinogenicity. This study first synthesized a hapten of Sudan 4 and produced the monoclonal antibody for immunoassay of these red dyes. The hapten was synthesized by coupling 4-amino-3-methylbenzoic acid to o-toluidine to obtain an intermediate hapten and then the intermediate hapten was coupled to β-naphthol to obtain a tentative hapten. The generated monoclonal antibody showed broad specificity to the six Sudan dyes. After evaluation of different coating antigens, a heterologous competitive indirect immunoassay was developed to determine the six red dyes in egg yolk simultaneously. The crossreactivities for the six analytes were in a range of 64%–110% and the limits of detection were in a range of 0.08–0.2 ng/g depending on the compound. Intra- and inter-assay recoveries from the standards fortified blank samples ranged from 71.5% to 107.4% with coefficients of variation lower than 14.6%. ► A novel hapten of Sudan 4 was first synthesized. ► The monoclonal antibody against Sudan 4 was first produced. ► The antibody was highly specific to Sudan 4, Sudan 2 and Sudan G. ► The antibody also recognized Sudan 1, Sudan 3 and Pare red. ► An heterologous immunoassay was developed to determine six Sudan dyes in egg.