Johan Elf

Per Johan Sven Elf, (born May 8, 1975) is a Swedish biophysicist. He is professor of physical biology at Uppsala universitet and Wallenberg Scholar.

Biography
Johan Elf was born in 1975, in Molala, a small city in the Sweden. He studied at Uppsala University, where he obtained an MSc in Engineering in 2000 and a PhD in Biotechnology in 2004 on stochasticity in intracellular processes. His PhD supervisor was of Prof. Mans Ehrenberg. In 2005 he moved to Harvard University where he developed single molecule methods to study transcription factor kinetics in living cells under the supervision of Prof. Xiaoliang Sunney Xie. In 2008 he became senior lecturer in bioinformatics at Uppsala University and in 2013 he was appointed professor of physical biology. As of 2016 he is a member of the Chemistry class at the Royal Swedish Academy of Sciences.

Elf is a member of the board of Uppsala University and the board of the Swedish Royal Academy of Sciences

Research
Elf studies dynamic processes in bacterial cells using sensitive optical methods. His main contributions are in algorithms for spatially-dependent stochastic simulations, single molecule methods for studying molecular search kinetics in living cells  and antibiotic susceptibility testing.

Companies
In 2017 Elf founded Astrego Diagnostics AB together with Özden Baltekin and Ove Öhman. The company develops rapid antibiotic susceptibility tests based on the academic work from the Elf lab. Elf left the company in 2022 when it was acquired by Sysmex Corporation. Sysmex Astrego was awarded the 8M£ Longitude Prize on AMR in 2024.

In 2022 Elf co-founded Bifrost Biosystems (Boston, MA) with Johan Paulsson, Paul Blainey and George Church.