After studying chemistry at the Ecole Normale Supérieure in Paris, Lina El Hajji started exploring the interface between chemistry and biology and earned a Master degree in Chemistry and Life Sciences. She conducted her PhD at the Laboratoire des Biomolécules at Sorbonne Université under the supervision of Prof Arnaud Gautier, working on the engineering of chemogenetic fluorescent reporters for advanced biological imaging. Using a concerted strategy of molecular engineering and directed evolution, she developed a near-infrared fluorescent chemogenetic reporter for multicolor imaging in cells and living organisms and inducing protein proximity. She also developed chemogenetic reporters compatible with fluorescence lifetime multiplexing. She is currently a postdoctoral researcher at the Laboratoire Chimie Physique and Chimie du Vivant at Sorbonne Université.