论文部分内容阅读
Identification and quantification of bacterial cells are of great importance for food safety,public health,and environment monitoring.However,traditional bacterial analytical methods are laborious and time-consuming,especially the culture-based methods are only suitable for viable and cultivable cells.1 The development of digital analysis based on droplet microfluidics provides a new experimental platform for biology assays.By distributing the target cells among many droplets,each droplet contains no more than one cell.Thus,this method has a great ability to characterize individual cells in a population.In addition,it can be used for accurate quantification based on the Poisson distribution.2 In our work,a T-junction was introduced in a flow-focusing chip to generate small volume of droplets,which could improve the signal-to-noise ratio.A fiber optic spectrometer was used to collect the fluorescence signal.Accurate counting of bacterial density at a range of 1.0 × 104-1.0 × 107 cells/mL can be accomplished in 5 minutes.Compared with traditional counting methods,this method offers a rapid and absolute quantification for bacterial cells.Moreover,the proposed method promises a broad range of application in particle quantification and bacterial identification.