Development of a rapid detection method for Staphylococcus aureus in milk based on magnetic separation using amino modified silica coated magnetic nanoparticles and polymerase chain reaction

In this study, the synthesis of amino-modified silica-coated magnetic nanoparticles were optimized, the optimal nanoparticles were used to adsorb a trace amount of genetic DNA from Staphylococcus aureus in milk, and then the complexes were used as DNA templates to be added into PCR.The limit of detection could reach 100 CFU/m L.The DNA and nanoparticle were directly added to PCR system during this process, without any steps of elution and purification. The cost of this magnetic separation method was quite low, for there was no need for nanoparticles to be labelled with biologic molecules such as antibody.This method has a great potential in the rapid detection of living organism.