A surface topography assisted droplet manipulation platform for biomarker detection and pathogen identification.
This paper reports a droplet microfluidic, sample-to-answer platform for the detection of disease biomarkers and infectious pathogens using crude biosamples. The platform exploited the dual functionality of silica superparamagnetic particles (SSP) for solid phase extraction of DNA and magnetic actuation. This enabled the integration of sample preparation and genetic analysis within discrete droplets, including the steps of cell lysis, DNA binding, washing, elution, amplification and detection. The microfluidic device was self contained, with all reagents stored in droplets, thereby eliminating the need for fluidic coupling to external reagent reservoirs. The device incorporated unique surface topographic features to assist droplet manipulation. Pairs of micro-elevations were created to form slits that facilitated efficient splitting of SSP from droplets. In addition, a compact sample handling stage, which integrated the magnet manipulator, the droplet microfluidic device and a Peltier thermal cycler, was built for convenient droplet manipulation and real-time detection. The feasibility of the platform was demonstrated by analysing ovarian cancer biomarker Rsf-1 and detecting Escherichia coli with real time polymerase chain reaction and real time helicase dependent amplification.
Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA.
Yi
Y
Zhang
Seungkyung
S
Park
Kelvin
K
Liu
Jennifer
J
Tsuan
Samuel
S
Yang
Tza-Huei
TH
Wang
D015415:Biomarkers / Q000032:analysis*; D004247:DNA / Q000302:isolation & purification; D004587:Electrophoresis, Agar Gel; D004926:Escherichia coli / Q000302:isolation & purification; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D044085:Microfluidics / Q000295:instrumentation*; D009687:Nuclear Proteins / Q000097:blood; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D016133:Polymerase Chain Reaction; D012822:Silicon Dioxide / Q000737:chemistry; D052616:Solid Phase Extraction; D015534:Trans-Activators / Q000097:blood
D015415:Biomarkers; D009687:Nuclear Proteins; C452851:RSF1 protein, human; D015534:Trans-Activators; D012822:Silicon Dioxide; D004247:DNA