µ-Laboratory for the Analysis and Separation of chromosomes: new tool for fast typing of bacterial, yeast, and mammalian cells – MicroLAS

We recently developed, patented, and successfully transferred a technology for DNA purification, enrichment, and separation. This technology coined µLAS involves an electric field and a counter hydrodynamic flow in viscoelastic liquids, in which transverse forces oriented toward the walls occur. These forces increase with DNA molecular weight (MW) and hence induce a progressive reduction in DNA migration speed that triggers size separation in microfluidic channels as well as in capillaries. Therefore with conventional microfluidic control systems of pressure and electric field, the transport of DNA can be finely controlled. More specifically using commercial Capillary Electrophroresis, this technology allows us to perform DNA separation in the 0.1-5 kbp with unrivalled sensitivity of 20 pg/mL with an operation time of ~10 minutes. In this proposal we aim to bring this technology one step ahead and perform the operations of separation, enrichment and purification for virtually every DNA molecular weight. We target academic and industrial needs in third generation sequencing, bacteriology, epidemiology, and cancer diagnostics. For this we will optimize the separation mechanism according to rational rules determined by specific physics models of flows in microchannels. More specifically, we intend to perform original experimental and theoretical researches on visco-elastic lift forces using different families of polymer solutions (WP2). Our goal is the development of a predictive platform to reach µLAS optimal performances. We will then confirm or invalidate the predictions of our platform by running separation experiments with DNA molecules of increasing molecular weight (WP3), and obtain optimal separation performances for the different DNA size ranges targeted in this project. We then wish to investigate whether enhanced separation performances for high molecular weight molecules can be reached with temporal modulations of the electric field (WP4). Note that WP3 and WP4 are mutually reinforcing: both aim to gradually improve the features of µLAS for DNA separation. The final task of this project (WP5) is devoted to the specification of a prototype for strain typing and/or quality control of bioprocesses, such as third generation DNA sequencing. Our project will be accomplished by LAAS and LRP, which are two laboratories expert in DNA separation in microfluidic systems and complex fluids hydrodynamics, respectively. Developments will be transferred to an SME company Picometrics for industrial prototyping.