About the Authors

Simone Kredel

Affiliation Institute of General Zoology and Endocrinology, University of Ulm, Ulm, Germany

Franz Oswald

Affiliation Department of Internal Medicine I, University of Ulm, Ulm, Germany

Karin Nienhaus

Affiliation Institute of Biophysics, University of Ulm, Ulm, Germany

Karen Deuschle

Affiliation Institute of Biophysics, University of Ulm, Ulm, Germany

Carlheinz Röcker

Affiliation Institute of Biophysics, University of Ulm, Ulm, Germany

Michael Wolff

Affiliations Institute of General Zoology and Endocrinology, University of Ulm, Ulm, Germany, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany

Ralf Heilker

Affiliation Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany

G. Ulrich Nienhaus

Affiliations Institute of Biophysics, University of Ulm, Ulm, Germany, Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America

Jörg Wiedenmann

joerg.wiedenmann@noc.soton.ac.uk

Affiliations Institute of General Zoology and Endocrinology, University of Ulm, Ulm, Germany, National Oceanography Centre, University of Southampton, Southampton, United Kingdom

Competing Interests

A US patent application covering mRuby and its applications is pending.

Author Contributions

Conceived and designed the experiments: FO GUN JW. Performed the experiments: SK FO KN KD CR JW. Analyzed the data: SK GUN JW. Contributed reagents/materials/analysis tools: FO JW. Wrote the paper: SK GUN JW. Contributed to discussions: MW RH.