Detection of staphylococcal enterotoxin in foods

A method has been developed for the detection of staphylococcal enterotoxin A in the boiled rice extract. The procedure utilized was the batch adsorption of enterotoxin from the cell-free culture supernatant by CG-50 ion exchange resin at pH 5.6. The enterotoxin was eluted by various concentrations of elution solution with different pH values. The lyophilized eluate was dissolved in Phosphate Buffer Saline (PBS) solution and analyzed with a quantitative double diffusion method. The desorption of enterotoxin from ion exchange resin appeared to be less effective by increasing the concentration of elution solution than by elevating the pH value of elution solution. The pH below 6.2 seemed to lose the ability to elute the enterotoxin from ion exchanger but enough to elimate non-specific extra proteins. The quantitative double diffusion method was able to detect enterotoxin in food with approximation in quantitation.