title: LED Thermo Flow - Combining Optogenetics with Flow Cytometry.
abstract: Optogenetic tools allow isolated, functional investigations of almost any signaling molecule within complex signaling pathways. A major obstacle is the controlled delivery of light to the cell sample and hence the most popular tools for optogenetic studies are microscopy-based cell analyses and in vitro experiments. The flow cytometer has major advantages over a microscope, including the ability to rapidly measure thousands of cells at single cell resolution. However, it is not yet widely used in optogenetics. Here, we present a device that combines the power of optogenetics and flow cytometry: the LED Thermo Flow. This device illuminates cells at specific wavelengths, light intensities and temperatures during flow cytometric measurements. It can be built at low cost and be used with most common flow cytometers. To demonstrate its utility, we characterized the photoswitching kinetics of Dronpa proteins in vivo and in real time. This protocol can be adapted to almost all optically controlled substances and substantially expands the set of possible experiments. More importantly, it will greatly simplify the discovery and development of new optogenetic tools.
authors.affiliation: Max-Planck Institute for Immunobiology und Epigenetics; Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg; Centre for Biological Signaling Studies, BIOSS, University of Freiburg; brenker@ie-freiburg.mpg.de.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Brenker
authors.affiliation: Max-Planck Institute for Immunobiology und Epigenetics; Albert-Ludwigs-Universität.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Osthof
authors.affiliation: Max-Planck Institute for Immunobiology und Epigenetics; Centre for Biological Signaling Studies, BIOSS, University of Freiburg.
authors.forename: Jianying
authors.initials: J
authors.lastname: Yang
authors.affiliation: Max-Planck Institute for Immunobiology und Epigenetics; Centre for Biological Signaling Studies, BIOSS, University of Freiburg; Institute for Biology III (Mol. Immunology), Albert-Ludwigs-Universität.
authors.forename: Michael
authors.initials: M
authors.lastname: Reth
mesh_terms: D002460:Cell Line; D005434:Flow Cytometry; D006801:Humans; D008027:Light; D062308:Optogenetics; D013696:Temperature