Olivier Siri
Aix-Marseille University, Marseille France
Who is Olivier Siri ?
Dr. Olivier Siri, Director of Research at CNRS since 2019, leads a distinguished team at Aix-Marseille University's Centre Interdisciplinaire de Nanoscience de Marseille (CINaM). His research focuses on chromophores and macrocycles, contributing significantly to molecular chemistry.
Dr. Siri earned his PhD in 1997 from the University of Burgundy, specializing in nitric oxide carriers under Professor Roger Guilard. He pursued postdoctoral research with Professor Kevin M. Smith at the University of California, Davis, focusing on porphyrin synthesis, followed by a stint at the University of Neuchâtel exploring new phototherapy strategies. Joining CNRS in 1999 at the University of Strasbourg, he later moved to Aix-Marseille University in 2005, where he continues to make impactful contributions to the field.
ColorFlux: when curiosity meets serendipity
Sometimes, breakthroughs don’t come from planned experiments, but from what happens when things don’t go as expected.
That’s exactly how ColorFlux was born.
Chemists Olivier Siri and Michel Camplo were developing phenazine molecules intended to serve as antibacterial agents or adjuvants. Alongside them, Mrunal Patil and Jean-Michel Bolla, an expert in bacterial transport, began screening the compounds.
But the initial results? Disappointing. No strong antibacterial effect. No obvious results.
But then, something unexpected happened.
The team noticed that certain bacteria were changing color depending on their efflux activity, a subtle visual clue tied to how cells pump out foreign substances. What started as an incidental observation soon turned into a full-fledged research question:
Could these compounds be used to detect efflux behavior in bacteria?
The answer was yes, and the result is ColorFlux, a simple yet powerful colorimetric test that visually reveals bacterial efflux activity in minutes. No PCR. No fancy machines. Just color change.
A sibling technology: GlowMito
What makes the ColorFlux story even more striking is how quickly it followed the release of another successful tool: GlowMito.
Just four months earlier, GlowMito, a live-cell mitochondrial probe, had been released by Olivier Siri’s and Guy Lenaers.
Originally derived from the same phenazine family, GlowMito was developed to help researchers image mitochondria without altering cell physiology , with high specificity, minimal background, and easy-to-handle protocols.
GlowMito is designed for:
- Live-cell mitochondrial tracking
- Co-labeling with other fluorophores (compatible with GFP)
- High signal retention for up to 3 days without washing
This incredible pace speaks volumes about Dr. Siri’s vision, and his desire to transfer accessible, useful technologies to researchers everywhere.
Fluorescence to color change: A shared vision
ColorFlux isn’t just a colorimetric test. It’s a window into bacterial behavior, designed for any lab, no matter how high-tech. It's ideal for:
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Quickly identifying efflux mutants and antibioresistant strains
- Evaluating potential inhibitors
- Teaching mechanisms of antibiotic resistance visually
And GlowMito continues to bring mitochondria to life under the microscope, where red fluorescence meets scientific clarity.
Two products. One molecule family. A whole lot of possibility.
Olivier Siri's ColorFlux publication
Mrunal Patil, Tatiana Munteanu, Gaël Brasseur, Carolina Ferreira, Sofia Santos Costa, Isabel Couto, Mohd Athar, Elisa Asunis, Attilio Vittorio Vargiu, Miguel Viveiros, Carole DiGiorgio, Frédéric Brunel, Jean-Manuel Raimundo, Michel Camplo, Olivier Siri, Jean-Michel Bolla —Unlocking the Gates: A Novel Diagnostic Molecule for Quantifying Efflux Levels in Gram-Positive Bacteria. doi: 10.1002/adhm.2024041451.