Plastic polymers for efficient DNA microarray hybridization : 1 Application to microbiological diagnostics

2 Fabrication of microarray devices using traditional glass slides is not easily 3 adaptable to integration into microfluidic systems. There is thus a need for the 4 development of polymeric materials showing a high hybridization signal to 5 background ratio enabling sensitive detection of microbial pathogens. We have 6 developed such plastic supports suitable for highly sensitive DNA microarray 7 hybridizations. The proof-of-concept of this microarray technology was made 8 through detection of four human respiratory viruses that were amplified and 9 labelled with a fluorescent dye via a sensitive reverse transcriptase PCR (RT10 PCR) assay. The microarray hybridization performance with plastic supports 11 made of PMMA-VSUVT or Zeonor 1060R was compared to that with high 12 quality glass slide microarrays using both passive and microfluidic hybridization 13 systems. A specific hybridization signal to background ratio comparable to the 14 high quality commercial glass slides was achieved with both polymeric 15 substrates. Microarray hybridizations demonstrated an analytical sensitivity 16 equivalent to approximately 100 viral genome copies per RT-PCR reaction which 17 is at least 100-fold more sensitive than previously reported DNA hybridizations on 18 plastic support. Testing of these plastic polymers using a microfluidic microarray 19 hybridization platform also showed results that were comparable to glass 20 support. In conclusion, PMMA-VSUVT and Zeonor 1060R are both suitable for 21 highly sensitive microarray hybridizations. 22