Development and Validation of a Monoclonal Antibody-Based Indirect Competitive ELISA for the Detection of Sudan I in Duck Eggs and Crystal Violet in Carp

摘要

In this study, two specific monoclonal antibodies, one for Sudan I and the other for leucocrystal violet, were prepared and then used to develop a sensitive indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for the detection of two illegal synthetic dyes: Sudan I in duck egg and crystal violet in fish muscle. The Sudan I-specific antibody 1H7 was of the IgG2b isotype and had an IC50 of 3.1 mu g L-1. Additionally, the crystal violet-specific antibody 4B10 was of the IgG2a isotype and had an IC50 of 5.3 mu g L-1. Based on these antibodies, the limit of detection (LOD), recoveries, and coefficient of variation of the ic-ELISA developed for the detection of Sudan I residues in duck egg samples were 0.6 mu g kg(-1), 83.6 +/- 113.8 %, and less than 8.4 %, and the values of the ic-ELISA developed for the detection of leucocrystal violet residues in fish muscle samples were 1.2 mu g kg(-1), 90.8 +/- 108.4 %, and less than 12.3 %, respectively. Both assays exhibited a positive correlation (r > 0.99) with the results of HPLC-MS run on the samples. These data indicate that the developed ic-ELISAs are reliable and will be very reliable screening methods for the detection of the illegal dyes Sudan I and crystal violet in duck egg and fish muscle, respectively.