Three-dimensional spot arrays add another benefit to the system (a combination of microarray technologies and microfluidics) since they increase the sensitivity and the dynamic range of the detection. The three-dimensional spot arrays in combination with a modular microfluidic system were successfully evaluated with the detection of meningococci in patients.
As shown in the gallery, we have combined both approaches – microarray technologies and microfluidics – in order to include in a microfluidic system the advantages micro-arrays offer for the analysis of biological samples.
In addition to this, due to the three-dimensional matrix of the spots, the capacity of the arrays and the dynamic range for the detection could be improved. The array were embedded in a modular microfluidic system covering not only the detection steps but the complete analysis, which started with sample uptake, overall lysis and DNA extraction to PCR and ended with the hybridization with an optical detection. Test system and motivation for the development of the above platform was stimulated by the need to detect meningococci in a patient's liquor while at their bedside.
The experimental set-up:
Different modules were designed to perform one of the above described steps of the biochemical cascade. As shown in the gallery, cell lysis and DNA purification were performed by magnetic beads located inside a chip based chamber. Resuspension and mixing of the beads and sample were performed with the help of a device-based mobile magnet.
Analyte amplification was realised as continuous flow PCR  and the needed actuation was supplied by the instrument as well. Respective microfluidic chips were injection moulded in a variety of thermoplastic polymers, namely cyclo-olefin-polymer (COP, tradename Zeonor) and cyclo-olefin-copolymer (COC, trade name: Topas).