Competitive direct ELISA based on a monoclonal antibody for detection of Ochratoxin A in dried fig samples

Abstract

A monoclonal antibody (MAb) generated against Ochratoxin A (OTA) has been used in a competitive direct enzyme linked immunosorbent assay (cdELISA) for the detection of OTA in dried figs obtained from the Spanish retail market. Fifty per cent inhibition of the maximum binding was obtained with an OTA concentration of 2 ng/mL, and the detection limit for OTA in solution was 0.18 ng/mL, corresponding to 3.15 ng OTA per gram of sample. OTA was detected in 19 (54.3%) out of 35 samples of dried figs analysed, with concentrations that ranged from 3.15 to 277 ng/g. Five samples contained OTA concentrations above the tolerable level set by EC regulations for dried vine fruits (10 ng/g). The MAb-based cdELISA assay developed in this work could be effectively applied for OTA screening in dried figs. © 2012 Copyright Taylor and Francis Group, LLC.