title: Multiplex isothermal solid-phase recombinase polymerase amplification for the specific and fast DNA-based detection of three bacterial pathogens.
abstract: We report on the development of an on-chip RPA (recombinase polymerase amplification) with simultaneous multiplex isothermal amplification and detection on a solid surface. The isothermal RPA was applied to amplify specific target sequences from the pathogensNeisseria gonorrhoeae,Salmonella entericaand methicillin-resistantStaphylococcus aureus(MRSA) using genomic DNA. Additionally, a positive plasmid control was established as an internal control. The four targets were amplified simultaneously in a quadruplex reaction. The amplicon is labeled during on-chip RPA by reverse oligonucleotide primers coupled to a fluorophore. Both amplification and spatially resolved signal generation take place on immobilized forward primers bount to expoxy-silanized glass surfaces in a pump-driven hybridization chamber. The combination of microarray technology and sensitive isothermal nucleic acid amplification at 38 °C allows for a multiparameter analysis on a rather small area. The on-chip RPA was characterized in terms of reaction time, sensitivity and inhibitory conditions. A successful enzymatic reaction is completed in <20 min and results in detection limits of 10 colony-forming units for methicillin-resistantStaphylococcus aureusandSalmonella entericaand 100 colony-forming units forNeisseria gonorrhoeae. The results show this method to be useful with respect to point-of-care testing and to enable simplified and miniaturized nucleic acid-based diagnostics. FigureThe combination of multiplex isothermal nucleic acid amplification with RPA and spatially-resolved signal generation on specific immobilized oligonucleotides.
authors.affiliation: Fraunhofer Institute for Biomedical Engineering IBMT, Branch Potsdam, Am Muehlenberg 13, 14476 Potsdam-Golm, Germany ; Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kersting
authors.affiliation: Fraunhofer Institute for Biomedical Engineering IBMT, Branch Potsdam, Am Muehlenberg 13, 14476 Potsdam-Golm, Germany.
authors.forename: Valentina
authors.initials: V
authors.lastname: Rausch
authors.affiliation: Fraunhofer Institute for Biomedical Engineering IBMT, Branch Potsdam, Am Muehlenberg 13, 14476 Potsdam-Golm, Germany ; Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany.
authors.forename: Frank F
authors.initials: FF
authors.lastname: Bier
authors.affiliation: Fraunhofer Institute for Biomedical Engineering IBMT, Branch Potsdam, Am Muehlenberg 13, 14476 Potsdam-Golm, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: von Nickisch-Rosenegk
keywords: DNA sensor; Isothermal amplification; Microchip; Point-of-care; RPA