Micro-magnet arrays for specific single bacterial cell positioning

• Published in: Journal of magnetism and magnetic materials Vol. 380; pp. 72 - 77
• Main Authors: Pivetal, Jérémy, Royet, David, Ciuta, Georgeta, Frenea-Robin, Marie, Haddour, Naoufel, Dempsey, Nora M., Dumas-Bouchiat, Frédéric, Simonet, Pascal
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.04.2015; Elsevier
• Subjects: Arrays; Bacteria; Electric power; Engineering Sciences; Escherichia coli; Heterogeneity; Magnetic bacterial cell labeling; Magnetic films; Magnetic micropatterning; Micro and nanotechnologies; Microbiology; Microelectronics; Microsystems; Pathogens; Platforms; Single cell analysis; Single cell micro-array; Strategy; Microsystems; Single cell analysis; Magnetic micropatterning; Single cell micro-array; Magnetic bacterial cell labeling
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2014.09.068

In various contexts such as pathogen detection or analysis of microbial diversity where cellular heterogeneity must be taken into account, there is a growing need for tools and methods that enable microbiologists to analyze bacterial cells individually. One of the main challenges in the development of new platforms for single cell studies is to perform precise cell positioning, but the ability to specifically target cells is also important in many applications. In this work, we report the development of new strategies to selectively trap single bacterial cells upon large arrays, based on the use of micro-magnets. Escherichia coli bacteria were used to demonstrate magnetically driven bacterial cell organization. In order to provide a flexible approach adaptable to several applications in the field of microbiology, cells were magnetically and specifically labeled using two different strategies, namely immunomagnetic labeling and magnetic in situ hybridization. Results show that centimeter-sized arrays of targeted, isolated bacteria can be successfully created upon the surface of a flat magnetically patterned hard magnetic film. Efforts are now being directed towards the integration of a detection tool to provide a complete micro-system device for a variety of microbiological applications. 1.We report a new approach to selectively micropattern bacterial cells individually upon micro-magnet arrays.2.Permanent micro-magnets of a size approaching that of bacteria could be fabricated using a Thermo-Magnetic Patterning process.3.Bacterial cells were labeled using two different magnetic labeling strategies providing flexible approach adaptable to several applications in the field of microbiology.