Simultaneous recording of multiple cellular signaling events by frequency- and spectrally-tuned multiplexing of fluorescent probes
Michelina Kierzek,
Parker E Deal,
Evan W Miller,
Shatanik Mukherjee,
Dagmar Wachten,
Arnd Baumann,
U Benjamin Kaupp,
Timo Strünker,
Christoph Brenker
Affiliations
Michelina Kierzek
Centre of Reproductive Medicine and Andrology, University of Münster, Münster, Germany; CiM-IMPRS Graduate School, University of Münster, Münster, Germany
Parker E Deal
Department of Chemistry, University of California, Berkeley, Berkeley, United States
Department of Chemistry, University of California, Berkeley, Berkeley, United States; Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
Centre of Reproductive Medicine and Andrology, University of Münster, Münster, Germany; Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
Fluorescent probes that change their spectral properties upon binding to small biomolecules, ions, or changes in the membrane potential (Vm) are invaluable tools to study cellular signaling pathways. Here, we introduce a novel technique for simultaneous recording of multiple probes at millisecond time resolution: frequency- and spectrally-tuned multiplexing (FASTM). Different from present multiplexing approaches, FASTM uses phase-sensitive signal detection, which renders various combinations of common probes for Vm and ions accessible for multiplexing. Using kinetic stopped-flow fluorimetry, we show that FASTM allows simultaneous recording of rapid changes in Ca2+, pH, Na+, and Vm with high sensitivity and minimal crosstalk. FASTM is also suited for multiplexing using single-cell microscopy and genetically encoded FRET biosensors. Moreover, FASTM is compatible with optochemical tools to study signaling using light. Finally, we show that the exceptional time resolution of FASTM also allows resolving rapid chemical reactions. Altogether, FASTM opens new opportunities for interrogating cellular signaling.
