Label free dynamic imaging: application to phage
infected bacteria

Martine Boccara, Viviane Ravet, Didier Debros, Olivier Thouvenin, Claude Boccara

► To cite this version:

Martine Boccara, Viviane Ravet, Didier Debros, Olivier Thouvenin, Claude Boccara. Label free dynamic imaging: application to phage infected bacteria. PHAGES in LYON, Nov 2023, Lyon, France. hal-04793490

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Submitted on 20 Nov 2024

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Distributed under a Creative Commons Attribution 4.0 International License
# Label free dynamic imaging: application to phage infected bacteria

Martine Boccara¹,², Viviane Ravet³, Didier Debros³, Olivier Thouvenin¹ and Albert Claude Boccara¹

¹Institut Langevin, ESPCI Paris, CNRS, PSL University, 1 rue Jussieu, 75005 Paris, France

²Atelier de Bioinformatique, ISYEB, UMR 7205, MNHN, Sorbonne Universités, 45 rue Buffon 75005 Paris, France

³Université Clermont Auvergne, CNRS, Laboratoire Microorganismes: Génome et 6 Environnement, F-63000 CLERMONT-FERRAND, FRANCE

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## Conclusions

**Label free methods are useful when labelling cannot be used**
We showed that we can **follow virus infection without using fluorescence** and this method can be applied to any virus (currently to viral infection of algae)
We need to better characterize the distribution of signal within the cells ("viral factories"?) during infection and compare it to fluorescent markers distribution.

During 2.5hrs we observed:

**A** A strong initial signal which disappears in 10min and was due to agar gel relaxation when introduced in the device (doublets in same direction and present also in non infected control)

**B** Signal (40-45 min after adsorption) localized with cells (not observed in control) suggesting correlation between signal increasing and viral multiplication. The presence of a doublets suggesting an interaction between infected bacteria and the gel.

**C** About 2hrs after adsorption a second increase in signal (5 times stronger than the first one) suggesting a second viral burst. This signal was distributed between two types of strong spots (possibly exploding cells) and signal within cells (D).

Shortly after the gel collapsed. Virus production was measured (not shown)

## References

Boccara, M., Fedala Y., Vénien-Bryan C., Bailly-Bechet M., Bowler C., Boccara A.C., Full field interferometry for counting and differentiating aquatic biotic nanoparticles: from laboratory to Tara Oceans. Biomed Opt Express Vol. 7, 3736-3746, (2016).

(b) Houda Bey, Florent Charton, Helena Cruz de Carvalho, Shun Liu, Richard

G. Dorrell, Chris Bowler, Claude Boccara & Martine Boccara (2022): Dynamic Cell Imaging: application to the diatom *Phaeodactylum tricornutum* under environmental stresses, European Journal of Phycology, DOI: 10.1080/09670262.2022.2081732