Highly efficient and specific separation of from lettuce and milk using Dynabeads protein G conjugates.

An immunomagnetic separation method using antibody-coated Dynabeads Protein G was developed for specific and efficient separation of in lettuce and whole milk. The amount of immunomagnetic beads (IMBs) and conjugation conditions were optimized. A high capture efficiency was obtained with 0.4 mg of IMBs, an immunoreaction time of 20 min, and a separation time of 1 min without wash. Under optimal conditions, the capture efficiency (CE) for 10-10 CFU/mL of was higher than 91.46%. The IMBs showed high specificity even with a high constant number (10 CFU/mL) of , , and . The CE of IMBs against at concentrations from 10 to 10 CFU/mL ranged from 78.70 to 94.77% for lettuce and 60.0 to 73.27% for milk samples. This IMS can be an appropriate selection for combining with bacterial detection method or efficient isolation procedure for from foods.