Chemiluminescent imaging detection of staphylococcal enterotoxin C1 in milk and water samples

A sensitive, simple and rapid technique for high throughput simultaneous detection of staphylococcal enterotoxin C1 (SEC1) has been developed. The proposed method has the advantage of showing the specificity of enzyme-linked immunosorbent assays (ELISA), sensitivity of luminol-based enhanced chemiluminescence (ECL) assay, and high throughput of chemiluminescence (CL) imaging assay. It was based on a standard sandwich immunoassay format; 96-well ELISA plates were used as solid phase material. A commercial high-sensitivity cooled CCD camera has been applied to image the weak CL. Under the optimum conditions, the increased CL intensity was proportional with the concentration of SEC1 in the range of 8.0–125.0 ng ml−1 and the detection limit was 0.5 ng ml−1 (3σ). The relative standard deviation (RSD) for eight parallel measurements of 25.0 ng ml−1 SEC1 was 0.06. The proposed method has been successfully applied to the determination of SEC1 in milk and water samples. The results obtained compared well with those by ELISA.