title: Microbial detection in microfluidic devices through dual staining of quantum dots-labeled immunoassay and RNA hybridization.
abstract: This paper reported the development of a microfludic device for the rapid detection of viable and nonviable microbial cells through dual labeling by fluorescent in situ hybridization (FISH) and quantum dots (QDs)-labeled immunofluorescent assay (IFA). The coin sized device consists of a microchannel and filtering pillars (gap=1-2 microm) and was demonstrated to effectively trap and concentrate microbial cells (i.e. Giardia lamblia). After sample injection, FISH probe solution and QDs-labeled antibody solution were sequentially pumped into the device to accelerate the fluorescent labeling reactions at optimized flow rates (i.e. 1 and 20 microL/min, respectively). After 2 min washing for each assay, the whole process could be finished within 30 min, with minimum consumption of labeling reagents and superior fluorescent signal intensity. The choice of QDs 525 for IFA resulted in bright and stable fluorescent signal, with minimum interference with the Cy3 signal from FISH detection.
authors.affiliation: Division of Environmental Science and Engineering, National University of Singapore, Blk E1A, #07-03, Engineering Drive 2, Singapore 117576, Singapore.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
authors.forename: Liang
authors.initials: L
authors.lastname: Zhu
authors.forename: Hanhua
authors.initials: H
authors.lastname: Feng
authors.forename: Simon
authors.initials: S
authors.lastname: Ang
authors.forename: Fook Siong
authors.initials: FS
authors.lastname: Chau
authors.forename: Wen-Tso
authors.initials: WT
authors.lastname: Liu