Characterisation of the staphylococcal enterotoxin research method in a dairy product

The staphylococcal enterotoxin research method is a quantitative method, involving a sample preparation and an imunoenzymatic detection. In order to estimate its performance characteristics, a method characterisation is carried out with a single dairy product and for staphyloccal enterotoxin A. Statistical analysis shows that the method is linear over a contamination interval between 0 - 1 ng SEA per gram of cheese. The limit of detection is about 0.01 ng SEA per gram of cheese and the limit of quantification is about 0.04 ng SEA per gram of cheese. The intra laboratory repeatability and intermediate precision are estimated on two levels of contamination. The repeatability coefficient of variation is included between 3.1 % and 6.2 %, the intermediate precision coefficient of variation is included between 4.7 % and 11.0 %.