Production of a Sensitive Monoclonal Antibody to Sterigmatocystin and Its Application to ELISA of Wheat

Abstract

A hybridoma cell line capable of secreting sensitive and specific monoclonal antibody for sterigmatocystin (STG) was produced by fusing SP2/0 myeloma cells with spleen cells of female Balb/C mice immunized with STG hemiacetal−bovine serum albumin conjugate. The concentration of STG required to inhibit 50% of the binding of the monoclonal antibody in a competitive ELISA (cELISA) was 2.5 ng/mL. The apparent affinity dissociation constant of the monoclonal antibody was 2.3 × 10-9 ± 1.4 × 10-10 M-1. The cross-reactions of STG, O-methyl-STG, STG hemiacetal, aflatoxin B1 (AFB1), AFB2, AFG1, AFG2, and AFB1 hemiacetal with the antibody in the cELISA were 100, 0.4, 12.5, 0.4, 0.1, <0.1, <0.1, 6.25%, respectively. Sterigmatocystin could be detected reproducibly using the cELISA and quantified in spiked wheat samples at concentrations greater than 31 ppb using a simple methanol and aqueous potassium chloride extraction procedure. Keywords: Sterigmatocystin; ELISA; monoclonal; antibody; wheat