No abstract

Semiconductor quantum dot-conjugated antibodies were successfully developed to label Cryptosporidium parvum and Giardia lamblia. This novel fluorescence system exhibited superior photostability, gave 1.5-to 9-fold-higher signal-to-noise ratios than traditional organic dyes in detecting C. parvum, and allowed dualcolor detection for C. parvum and G. lamblia.

No abstract

A filter-based microfluidic device was combined with immunofluorescent labeling as a platform to rapidly detect microbial cells. The coin-sized device consisted of micro-chambers, micro-channels and filter weirs (gap = 1-2 microm), and was demonstrated to effectively trap and concentrate microbial cells (i.e., Cryptosporidium parvum and Giardia lamblia), which were larger in size than the weir gap. After sample injection, a staining solution containing fluorescently-labeled antibodies was continuously provided into the device (flow rate = 20 microl min(-1)) to flush the microbial cells toward the weirs and to accelerate the fluorescent labeling reaction. Using a staining solution that was 10 to 100 times more dilute than the recommended concentration used in a conventional glass method, those target cells with a fluorescent signal-to-noise ratio of 12 could be microscopically observed at single-cell level within 2 to 5 min prior to secondary washing.