MICROFLUIDIC MAGNETIC FLUIDIZED BED FOR BACTERIA EXTRACTION, GROWTH AND DETECTION

We present a two-step microfluidic assay for the rapid detection of bacteria in liquid samples based on a magnetic fluidized-bed recently developed by our group. First, an immunoextraction and preconcentration step of Salmonella typhimurium is performed with evaluated capture rates of 90%. Immediately thereafter the captured bacteria are cultured in situ with a constant flow of nutritionally rich medium. Their growth results in an expansion of the fluidized-bed enabling the direct detection of salmonella by visual monitoring. Moreover, the expansion times directly depend on the sample concentration, allowing precise quantifications of the initial bacteria coupled with a very high sensitivity.