Disposable microfluidic chip for rapid pathogen identification with DNA microarrays

This work presents the combination and acceleration of PCR and fluorescent labelling within a disposable microfluidic chip. The utilised geometry consists of a spiral meander with 40 turns, representing a cyclic-flow PCR system. The used reaction chemistry includes Cy3-conjugated primers leading to a one-step process accelerated by cyclic-flow PCR. DNA of three different bacterial samples (Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) was processed and successfully amplified and labelled with detection limits down to 10² cells per reaction. The specificity of species identification was comparable to the approach of separate PCR and labelling. The overall processing time was decreased from 6 to 1.5 h. We showed that a disposable polycarbonate chip, fabricated by injection moulding is suitable for the significant acceleration of DNA microarray assays. The reaction output led to high-sensitivity bacterial identification in a short time, which is crucial for an early and targeted therapy against infectious diseases.