Before using the assay in actual real samples, uncontaminated real samples were spiked with the microorganism to prepare the matrix. Four samples of infant food products, infant formula, rice noodles, milk and noodles were purchased from a local supermarket.Each sample (25 g or 25 mL) was mixed with 225 mL of LB and homogenized in a mortar to produce 1:10 produce homogenate.The homogenate was analyzed for the absence of the three target pathogens by culture methods. When no target bacteria weredetected, these food samples were used for further spike experiments.For the spike experiments, two sets of food samples wereprepared. The first set of four samples consisting of 25 g or 25mL of each sample mixed with 225 mL of LB, was prepared by adding only dead target cells at a final concentration of 107 CFU/g of C. sakazakii,S. aureus and B. cereus, respectively. After mixing thoroughly, two 1.5 mL tubes filled with 1 mL sample matrix were centrifuged at 900 g for 2 min to remove the large debris.