title: SpRET: highly sensitive and reliable spectral measurement of absolute FRET efficiency.
abstract: Contemporary research aims to understand biological processes not only by identifying participating proteins, but also by characterizing the dynamics of their interactions. Because Förster's Resonance Energy Transfer (FRET) is invaluable for the latter undertaking, its usage is steadily increasing. However, FRET measurements are notoriously error-prone, especially when its inherent efficiency is low, a not uncommon situation. Furthermore, many FRET methods are either difficult to implement, are not appropriate for observation of cellular dynamics, or report instrument-specific indices that hamper communication of results within the scientific community. We present here a novel comprehensive spectral methodology, SpRET, which substantially increases both the reliability and sensitivity of FRET microscopy, even under unfavorable conditions such as weak fluorescence or the presence of noise. While SpRET overcomes common pitfalls such as interchannel crosstalk and direct excitation of the acceptor, it also excels in removal of autofluorescence or background contaminations and in correcting chromatic aberrations, often overlooked factors that severely undermine FRET experiments. Finally, SpRET quantitatively reports absolute rather than relative FRET efficiency values, as well as the acceptor-to-donor molar ratio, which is critical for full and proper interpretation of FRET experiments. Thus, SpRET serves as an advanced, improved, and powerful tool in the cell biologist's toolbox.
authors.affiliation: Department of Physiology and Neurobiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
authors.forename: Shiri
authors.initials: S
authors.lastname: Levy
authors.forename: Christian D
authors.initials: CD
authors.lastname: Wilms
authors.forename: Eliaz
authors.initials: E
authors.lastname: Brumer
authors.forename: Joy
authors.initials: J
authors.lastname: Kahn
authors.forename: Lilach
authors.initials: L
authors.lastname: Pnueli
authors.forename: Yoav
authors.initials: Y
authors.lastname: Arava
authors.forename: Jens
authors.initials: J
authors.lastname: Eilers
authors.forename: Daniel
authors.initials: D
authors.lastname: Gitler
mesh_terms: D002477:Cells / Q000737:chemistry / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer / Q000295:instrumentation / Q000379:methods*; D057809:HEK293 Cells; D006801:Humans; D008164:Luminescent Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012680:Sensitivity and Specificity
chemical_list: D008164:Luminescent Proteins