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High-Throughput Monitoring of Bacterial Cell Density in Nanoliter Droplets: Label-Free Detection of Unmodified Gram-Positive and Gram-Negative Bacteria

Pacocha, Natalia and Bogusławski, Jakub and Horka, Michał and Makuch, Karol and Liżewski, Kamil and Wojtkowski, Maciej and Garstecki, Piotr (2021) High-Throughput Monitoring of Bacterial Cell Density in Nanoliter Droplets: Label-Free Detection of Unmodified Gram-Positive and Gram-Negative Bacteria. Analytical Chemistry, 93 (2). pp. 843-850. ISSN 0003-2700.

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Droplet microfluidics disrupted analytical biology with the introduction of digital polymerase chain reaction and single-cell sequencing. The same technology may also bring important innovation in the analysis of bacteria, including antibiotic susceptibility testing at the single-cell level. Still, despite promising demonstrations, the lack of a high-throughput label-free method of detecting bacteria in nanoliter droplets prohibits analysis of the most interesting strains and widespread use of droplet technologies in analytical microbiology. We use a sensitive and fast measurement of scattered light from nanoliter droplets to demonstrate reliable detection of the proliferation of encapsulated bacteria. We verify the sensitivity of the method by simultaneous readout of fluorescent signals from bacteria expressing fluorescent proteins and demonstrate label-free readout on unlabeled Gram-negative and Gram-positive species. Our approach requires neither genetic modification of the cells nor the addition of chemical markers of metabolism. It is compatible with a wide range of bacterial species of clinical, research, and industrial interest, opening the microfluidic droplet technologies for adaptation in these fields.

Item Type:Article
Related URLs:
URLURL TypeDescription
Pacocha, Natalia0000-0001-9543-7122
Bogusławski, Jakub0000-0003-0335-1802
Horka, Michał0000-0003-2554-2685
Makuch, Karol0000-0002-9769-7646
Liżewski, Kamil0000-0002-3350-4622
Wojtkowski, Maciej0000-0003-0599-0878
Garstecki, Piotr0000-0001-9101-7163
Additional Information:© 2020 American Chemical Society. Received: August 11, 2020; Accepted: November 10, 2020; Published: December 10, 2020. N.P. was supported by the National Science Centre funding based on decision number DEC-2014/12/W/NZ6/00454 (Symphony). P.G. was supported by EVO Drops no. 813786. M.H. was supported by the Foundation for Polish Science through the program TEAM TECH/2016-2/10. K.M. has received funding from the Polish National Agency for Academic Exchange. J.B. and M.W. were supported within the 2 × 2 PhotonVis project no. POIR.04.04.00-00-3D47/16-00 which is carried out within the TEAM TECH programme of the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund. This publication is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 666295 and from the financial resources for science in the years 2016–2019 awarded by the Polish Ministry of Science and Higher Education for the implementation of an international co-financed project. Author Contributions. N.P. and J.B. contributed equally. The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript. The authors declare no competing financial interest.
Funding AgencyGrant Number
National Science Centre (Poland)DEC-2014/12/W/NZ6/00454
Foundation for Polish ScienceTEAM TECH/2016-2/10
EVO Drops813786
Polish National Agency for Academic ExchangeUNSPECIFIED
European Regional Development FundPOIR.04.04.00-00-3D47/16-00
European Research Council (ERC)666295
Ministerstwo Nauki i Szkolnictwa Wyższego (MNiSW) UNSPECIFIED
Subject Keywords:Antimicrobial agents, Liquids, Bacteria, Fluorescence,Light
Issue or Number:2
Record Number:CaltechAUTHORS:20201215-141037377
Persistent URL:
Official Citation:High-Throughput Monitoring of Bacterial Cell Density in Nanoliter Droplets: Label-Free Detection of Unmodified Gram-Positive and Gram-Negative Bacteria. Natalia Pacocha, Jakub Bogusławski, Michał Horka, Karol Makuch, Kamil Liżewski, Maciej Wojtkowski, and Piotr Garstecki. Analytical Chemistry 2021 93 (2), 843-850; DOI: 10.1021/acs.analchem.0c03408
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:107097
Deposited By: George Porter
Deposited On:15 Dec 2020 23:21
Last Modified:20 Jan 2021 23:04

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