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Size-based sorting of dynamic bacterial clusters

Akbari, Elham LU ; Beech, Jason P. LU ; Kumra Ahnlide, Johannes LU orcid ; Wrighton, Sebastian LU orcid ; Nordenfelt, Pontus LU orcid and Tegenfeldt, Jonas O. LU orcid (2026) In Lab on a Chip
Abstract

Group A Streptococcus (GAS) forms highly deformable aggregates with broad variations in size and morphology, complicating controlled separation and biological analysis. Reliable methods to isolate fractions of GAS clusters with defined properties are essential for studying host–pathogen interactions that depend on cluster size. Here, we present a simple deterministic lateral displacement (DLD) microfluidic device to separate complex suspensions of bacterial aggregates into two size-enriched fractions. We use a DLD with a small displacement angle to accommodate the large range of particle sizes above the critical size. We introduce an intermediate outlet, in addition to the conventional zigzag and displacement outlets, to collect the... (More)

Group A Streptococcus (GAS) forms highly deformable aggregates with broad variations in size and morphology, complicating controlled separation and biological analysis. Reliable methods to isolate fractions of GAS clusters with defined properties are essential for studying host–pathogen interactions that depend on cluster size. Here, we present a simple deterministic lateral displacement (DLD) microfluidic device to separate complex suspensions of bacterial aggregates into two size-enriched fractions. We use a DLD with a small displacement angle to accommodate the large range of particle sizes above the critical size. We introduce an intermediate outlet, in addition to the conventional zigzag and displacement outlets, to collect the aggregates which exhibit a large dispersion due to their broad variety in shape and sizes close to the device critical diameter. In this way, we can demonstrate fractionation of GAS clusters with >90% purity based on effective size while causing minimal fragmentation or additional aggregation, as demonstrated by image analysis and dual-colour experiments. Finally, we show biological relevance through a live immune-cell assay, where human immune cells migrate more rapidly in the presence of larger GAS clusters than in smaller clusters or single bacteria. These results demonstrate that DLD-based separation provides biologically meaningful fractions of bacterial aggregates and enables new analyses of how cluster size influences immune responses.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
epub
subject
in
Lab on a Chip
publisher
Royal Society of Chemistry
external identifiers
  • pmid:41636785
  • scopus:105029299586
ISSN
1473-0197
DOI
10.1039/d5lc01111f
language
English
LU publication?
yes
id
a509a80c-13a2-41c3-9a1c-705c51c84def
date added to LUP
2026-02-20 13:17:09
date last changed
2026-02-21 03:37:58
@article{a509a80c-13a2-41c3-9a1c-705c51c84def,
  abstract     = {{<p>Group A Streptococcus (GAS) forms highly deformable aggregates with broad variations in size and morphology, complicating controlled separation and biological analysis. Reliable methods to isolate fractions of GAS clusters with defined properties are essential for studying host–pathogen interactions that depend on cluster size. Here, we present a simple deterministic lateral displacement (DLD) microfluidic device to separate complex suspensions of bacterial aggregates into two size-enriched fractions. We use a DLD with a small displacement angle to accommodate the large range of particle sizes above the critical size. We introduce an intermediate outlet, in addition to the conventional zigzag and displacement outlets, to collect the aggregates which exhibit a large dispersion due to their broad variety in shape and sizes close to the device critical diameter. In this way, we can demonstrate fractionation of GAS clusters with &gt;90% purity based on effective size while causing minimal fragmentation or additional aggregation, as demonstrated by image analysis and dual-colour experiments. Finally, we show biological relevance through a live immune-cell assay, where human immune cells migrate more rapidly in the presence of larger GAS clusters than in smaller clusters or single bacteria. These results demonstrate that DLD-based separation provides biologically meaningful fractions of bacterial aggregates and enables new analyses of how cluster size influences immune responses.</p>}},
  author       = {{Akbari, Elham and Beech, Jason P. and Kumra Ahnlide, Johannes and Wrighton, Sebastian and Nordenfelt, Pontus and Tegenfeldt, Jonas O.}},
  issn         = {{1473-0197}},
  language     = {{eng}},
  publisher    = {{Royal Society of Chemistry}},
  series       = {{Lab on a Chip}},
  title        = {{Size-based sorting of dynamic bacterial clusters}},
  url          = {{http://dx.doi.org/10.1039/d5lc01111f}},
  doi          = {{10.1039/d5lc01111f}},
  year         = {{2026}},
}