Development of a Competitive Enzyme Immunoassay Technique for the Detection of Peanut Traces in Gluten-free Products

The aim of this work was to develop a competititve enzymeimmunoassay technique, to detect the presence of traces of peanut in gluten-free products. Specific rabbit polyclonal antiserum against peanut was used as primary antibody. The optimal antigen concentration to be immobilized on the plate and the concentration of primary antibody to be used in competition was determined. The calibration curve was fitted using increasing concentrations of an extract of peanut product. The peanut product was extracted with Tris-HCl buffer 0.0625M with 3% sodium dodecylsulfate (SDS) and 2% sulphite (S) 0,1 M. All validation parameters studied were appropriate. Commercial samples of gluten-free products were analysed with this enzyme immunoassays and a commercial ELISA kit. Significant differences were observed in the quantitative results obtained with both methods; nevertheless the developed enzyme immunoassay could be used as screening method.