---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '22297'
abstract:
- lang: eng
  text: 'Determination of the rheological properties of cells is known to require
    active measurements, which largely depend on the internalization of mechanical
    probes. Here, we circumvent this problem via the introduction of Rheological focused
    light-induced cytoplasmic streaming (Rheo-FLUCS): an active, yet probe-free approach
    that leverages light-induced flows to access mechanical changes in complex systems.
    While Rheo-FLUCS is facilitated by thermoviscous expansion phenomena rather than
    external forces, here we show equivalence in its ability to measure relative viscoelastic
    properties. Specifically, we demonstrate a phase-lag equivalence with probe-dependent
    active microrheology in a wide range of physically different, yet chemically identical
    materials. We exemplify the utility of Rheo-FLUCS in three distinctly different
    biological systems: compound-treated mouse fibroblasts (NIH-3T3), genetically
    modified human osteoblasts (U2OS) to elucidate the role of myosins in cytoplasmic
    mechanics, and early ascidian oocytes of Phallusia mammillata at fertilization
    stage. Our biological use-cases exemplify the application versatility of Rheo-FLUCS,
    which in the future may use phase information as a marker for developmental success.'
acknowledgement: The authors gratefully acknowledge help from Dr. Benjamin Seelbinder,
  Mr. Claudius George, and Mr. Falk Elsner in designing and constructing the magnetic
  needle for force-driven rheology experiments. We thank Dr. Iain Patten for valuable
  discussions on the structure of the manuscript and Mr. Ivan Saraev for graphics
  support. I.D.S. and M.K. kindly acknowledge funding from the Life grant by Volkswagen
  Foundation (Life! grant no. 92772), Deutsche Forschungsgemeinschaft (DFG, German
  Research Foundation, Germany's Excellence Strategy, 2082/1 and grant no. 515462906),
  and the Hector Foundation. I.D.S. was additionally funded by the Karlsruhe Institute
  of Technology (Excellence Strategy via the Young Investigator Group Preparation
  Program). V.R.K., S.W., and M.K. thank the ERC Starting Grant GHOSTs (grant no.
  853619).
article_number: pgag190
article_processing_charge: Yes
article_type: original
author:
- first_name: Iliya D
  full_name: Stoev, Iliya D
  last_name: Stoev
- first_name: Madison
  full_name: Bolger-Munro, Madison
  id: 516F03FA-93A3-11EA-A7C5-D6BE3DDC885E
  last_name: Bolger-Munro
  orcid: 0000-0002-8176-4824
- first_name: Antonio
  full_name: Minopoli, Antonio
  last_name: Minopoli
- first_name: Susan
  full_name: Wagner, Susan
  last_name: Wagner
- first_name: Venkat Raghavan
  full_name: Krishnaswamy, Venkat Raghavan
  last_name: Krishnaswamy
- first_name: Elena
  full_name: Erben, Elena
  last_name: Erben
- first_name: Kai
  full_name: Weißenbruch, Kai
  last_name: Weißenbruch
- first_name: Nicola
  full_name: Maghelli, Nicola
  last_name: Maghelli
- first_name: Martin
  full_name: Bastmeyer, Martin
  last_name: Bastmeyer
- first_name: Carl-Philipp J
  full_name: Heisenberg, Carl-Philipp J
  id: 39427864-F248-11E8-B48F-1D18A9856A87
  last_name: Heisenberg
  orcid: 0000-0002-0912-4566
- first_name: Moritz
  full_name: Kreysing, Moritz
  last_name: Kreysing
biorxivid: 1
citation:
  ama: Stoev ID, Bolger-Munro M, Minopoli A, et al. Active and probe-free intracellular
    rheology via phase-sensitive thermoviscous flows. <i>PNAS Nexus</i>. 2026;5(6).
    doi:<a href="https://doi.org/10.1093/pnasnexus/pgag190">10.1093/pnasnexus/pgag190</a>
  apa: Stoev, I. D., Bolger-Munro, M., Minopoli, A., Wagner, S., Krishnaswamy, V.
    R., Erben, E., … Kreysing, M. (2026). Active and probe-free intracellular rheology
    via phase-sensitive thermoviscous flows. <i>PNAS Nexus</i>. Oxford University
    Press. <a href="https://doi.org/10.1093/pnasnexus/pgag190">https://doi.org/10.1093/pnasnexus/pgag190</a>
  chicago: Stoev, Iliya D, Madison Bolger-Munro, Antonio Minopoli, Susan Wagner, Venkat
    Raghavan Krishnaswamy, Elena Erben, Kai Weißenbruch, et al. “Active and Probe-Free
    Intracellular Rheology via Phase-Sensitive Thermoviscous Flows.” <i>PNAS Nexus</i>.
    Oxford University Press, 2026. <a href="https://doi.org/10.1093/pnasnexus/pgag190">https://doi.org/10.1093/pnasnexus/pgag190</a>.
  ieee: I. D. Stoev <i>et al.</i>, “Active and probe-free intracellular rheology via
    phase-sensitive thermoviscous flows,” <i>PNAS Nexus</i>, vol. 5, no. 6. Oxford
    University Press, 2026.
  ista: Stoev ID, Bolger-Munro M, Minopoli A, Wagner S, Krishnaswamy VR, Erben E,
    Weißenbruch K, Maghelli N, Bastmeyer M, Heisenberg C-PJ, Kreysing M. 2026. Active
    and probe-free intracellular rheology via phase-sensitive thermoviscous flows.
    PNAS Nexus. 5(6), pgag190.
  mla: Stoev, Iliya D., et al. “Active and Probe-Free Intracellular Rheology via Phase-Sensitive
    Thermoviscous Flows.” <i>PNAS Nexus</i>, vol. 5, no. 6, pgag190, Oxford University
    Press, 2026, doi:<a href="https://doi.org/10.1093/pnasnexus/pgag190">10.1093/pnasnexus/pgag190</a>.
  short: I.D. Stoev, M. Bolger-Munro, A. Minopoli, S. Wagner, V.R. Krishnaswamy, E.
    Erben, K. Weißenbruch, N. Maghelli, M. Bastmeyer, C.-P.J. Heisenberg, M. Kreysing,
    PNAS Nexus 5 (2026).
das_tickbox: '1'
dataavailabilitystatement: 'All data and materials are made available on Zenodo public
  repository under Creative Commons Attribution 4.0 International License: https://doi.org/10.5281/zenodo.20322020.'
date_created: 2026-07-13T09:50:12Z
date_published: 2026-06-01T00:00:00Z
date_updated: 2026-07-13T13:14:43Z
day: '01'
ddc:
- '570'
department:
- _id: CaHe
doi: 10.1093/pnasnexus/pgag190
external_id:
  biorxivid:
  - 10.1101/2025.04.07.647540
file:
- access_level: open_access
  checksum: bb2c89ea73da762ad6423ac299ac3533
  content_type: application/pdf
  creator: dernst
  date_created: 2026-07-13T13:13:56Z
  date_updated: 2026-07-13T13:13:56Z
  file_id: '22312'
  file_name: 2026_PNASNexus_Stoev.pdf
  file_size: 3073062
  relation: main_file
  success: 1
file_date_updated: 2026-07-13T13:13:56Z
has_accepted_license: '1'
intvolume: '         5'
issue: '6'
keyword:
- cell mechanics
- active microrheology
- noninvasiveness
- thermoviscous flows
- FLUCS
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
publication: PNAS Nexus
publication_identifier:
  eissn:
  - 2752-6542
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
researchdata_availability: yes
scopus_import: '1'
status: public
supplementarymaterial: yes
title: Active and probe-free intracellular rheology via phase-sensitive thermoviscous
  flows
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 5
year: '2026'
...