Novel chemiluminescent assay for staphylococcal enterotoxin B

An enzyme-linked immunosorbent assay, a horseradish peroxidase-catalyzed fluorogenic reaction, and chemiluminescence (CL) analysis have been combined to develop a sandwich ELISA for Staphylococcal enterotoxin B (SEB) using monoclonal antibodies for different epitopes of SEB. The enzyme catalyzed reaction of 3-(4-hydroxyphenyl propionate) with the urea complex of hydrogen peroxide produced a fluorescent dimer which was detected by chemiluminescence analysis. The CL response to SEB is linear in the range from 6.0 to 564 pg mL−1 (r = 0.9993), and the detection limit is 3.3 pg mL−1 (S/N = 3). Intra- and interassay coefficients of variation are <7.0% at three concentrations (24, 96 and 384 pg mL−1). The method was applied to the analysis of SEB in serum, lake water and milk samples. The results compared well with those obtained by conventional ELISAs.