Jean-francois ALLEMAND

Single-molecule experiments
Department of Physics
, updated on
25 November 2021
Laboratoire de physique de l’ENS (LPENS)
2ème étage, bureau L277
24, rue Lhomond 75231 Paris cedex 05
01 44 323493

At the research level I am interested in instrumentation to manipulate/visualize individual molecules to study biological molecules and their activity in real time. Since my thesis work I am used to interact with biologists and chemists around living systems. I try to maintain this practice in my teaching activities.

Field of research

We use the mechanical response of molecules and statistical physics to obtain information on the interactions between biomolecules (DNA/DNA, DNA/proteins,...) and the activity of some enzymes that act as molecular motors.

For this experimental approach, we develop methods for micromanipulation or visualization to study living objects.


1.         Rieu, M. et al. Parallel, linear, and subnanometric 3D tracking of microparticles with Stereo Darkfield Interferometry. Sci. Adv. 7, eabe3902 (2021).

2.         Bizard, A. H. et al. PICH and TOP3A cooperate to induce positive DNA supercoiling. Nat. Struct. Mol. Biol. 26, 267–274 (2019).

3.         Ding, F. et al. Single-molecule mechanical identification and sequencing. Nat. Methods 9, 367-U74 (2012).

4.         Saleh, O. A., Bigot, S., Barre, F.-X. & Allemand, J.-F. Analysis of DNA supercoil induction by FtsK indicates translocation without groove-tracking. Nat. Struct. Mol. Biol. 12, 436–440 (2005).

5.         Cogne-Laage, E. et al. Diaroyl(methanato)boron difluoride compounds as medium-sensitive two-photon fluorescent probes. Chem.- Eur. J. 10, 1445–1455 (2004).

6.         Allemand, J. F., Bensimon, D., Lavery, R. & Croquette, V. Stretched and overwound DNA forms a Pauling-like structure with exposed bases. Proc. Natl. Acad. Sci. U. S. A. 95, 14152–14157 (1998).