Microfluidic biochips for cell guidance and separation

Here the authors present a disposable biochip for the purpose of biological cell analysis. Standard lithographic processes were employed to create a master mould, which was then used in hot embossing to produce inexpensive plastic chips. This technology enabled us to fabricate channels and complex two-dimensional interconnecting structures in a range of thermoplastic materials (PMMA, polycarbonate, polystyrene). Dimensions of the channels were typically: width /spl ap/60 /spl mu/m and depth /spl ap/40 /spl mu/m. This resulted in optically transparent structures suitable for imaging of cells within the channels using an optically inverted microscope. The authors employed a prototype pumping system in order to transport the electrolyte solution, cells and reagents through the capillaries. These biochips and complementing experimental set-up resulted in the successful observation of the flow of human T-cells in these microchannels. This set-up also enabled the authors to observe the interaction of T-cells with the walls of the channels, which were covered with monoclonal antibodies imitating, to a certain extent, natural cell receptor/ligand interactions in capillary blood vessels.