Suitable molecular methods for a faster microbial identification in food and clinical samples have been explored and optimized during the last decades. However, most molecular methods still rely on time-consuming enrichment steps prior to detection, so that the microbial load can be increased and reach the detection limit of the techniques.In this chapter, we describe an integrated methodology that combines a microfluidic (lab-on-a-chip) platform, designed to concentrate cell suspensions and speed up the identification process in Saccharomyces cerevisiae , and a peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) protocol optimized and adapted to microfluidics. Microfluidic devices with different geometries were designed, based on computational fluid dynamics simulations, and subsequently fabricated in polydimethylsiloxane by soft lithography. The microfluidic designs and PNA-FISH procedure described here are easily adaptable for the detection of other microorganisms of similar size.
Keywords: Fluid mechanics; Microfluidics; Microorganism identification; Modeling; PNA-FISH; Pathogen detection.