title: Surface free energy activated high-throughput cell sorting.
abstract: Cell sorting is an important screening process in microbiology, biotechnology, and clinical research. Existing methods are mainly based on single-cell analysis as in flow cytometric and microfluidic cell sorters. Here we report a label-free bulk method for sorting cells by differentiating their characteristic surface free energies (SFEs). We demonstrated the feasibility of this method by sorting model binary cell mixtures of various bacterial species, including Pseudomonas putida KT2440, Enterococcus faecalis ATCC 29212, Salmonella Typhimurium ATCC 14028, and Escherichia coli DH5α. This method can effectively separate 10(10) bacterial cells within 30 min. Individual bacterial species can be sorted with up to 96% efficiency, and the cell viability ratio can be as high as 99%. In addition to its capacity of sorting evenly mixed bacterial cells, we demonstrated the feasibility of this method in selecting and enriching cells of minor populations in the mixture (presenting at only 1% in quantity) to a purity as high as 99%. This SFE-activated method may be used as a stand-alone method for quickly sorting a large quantity of bacterial cells or as a prescreening tool for microbial discrimination. Given its advantages of label-free, high-throughput, low cost, and simplicity, this SFE-activated cell sorting method has potential in various applications of sorting cells and abiotic particles.
authors.affiliation: Department of Mechanical Engineering and §Department of Civil and Environmental Engineering, University of Hawaii at Manoa , Honolulu, Hawaii 96822 United States.
authors.forename: Xinru
authors.initials: X
authors.lastname: Zhang
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: Yan
authors.forename: Zeyi
authors.initials: Z
authors.lastname: Jiang
authors.forename: Xinxin
authors.initials: X
authors.lastname: Zhang
authors.forename: Yi Y
authors.initials: YY
authors.lastname: Zuo
mesh_terms: D001419:Bacteria / Q000302:isolation & purification*; D002469:Cell Separation; D013293:Enterococcus faecalis / Q000302:isolation & purification / Q000502:physiology; D004926:Escherichia coli / Q000302:isolation & purification / Q000502:physiology; D046210:Microfluidic Analytical Techniques; D008856:Microscopy, Fluorescence; D016958:Pseudomonas putida / Q000302:isolation & purification / Q000502:physiology; D012486:Salmonella typhimurium / Q000302:isolation & purification / Q000502:physiology; D013053:Spectrophotometry; D055672:Static Electricity; D013500:Surface Tension; D013816:Thermodynamics