SPY555-BG is the benzylguanine derivative of our SPY555 fluorophore. It emits light in the orange part of the UV-ViS spectrum, it is fluorogenic, highly cell permeable and well suited for STED and SIM superresolution imaging. SPY555-BG can be imaged with a standard Cy5 filterset. It can be used for widefield, confocal, SIM or STED imaging in living or fixed cells and tissue. It has the same structure as MaP555-SNAP the name used in its original publication in Nature Chemistry1). SPY555-BG is an alternative to SNAP-Cell® TMR-Star, it has faster labeling kinetics.
Benzylguanine (BG) is the substrate of the self labeling tag SNAP-tag™*. Upon reaction with a BG derivative, SNAP-tag™* forms a covalent bond with the substrate and releases guanine. It allows to permanently attach a fluorescent label to any protein of interest (POI) expressed as SNAP-tag™* fusion.
|Absorbance maximum λabs||555 nm|
|Fluorescence maximum λfl||580 nm|
|Works on fixed cells?||Yes, any type of fixation method|
|Probe quantity||35 nmol|
|Fluorescence lifetime||2.4 ns|
|STED depletion wavelength||660 or 775 nm|
1. “A general strategy to develop cell permeable and fluorogenic probes for multicolour nanoscopy”; Lu Wang, et. al.; Nature Chemistry 12, 165-172, 2020.
*SNAP-tag™ and SNAP-Cell® are registered trademarks of New England Biolabs, Inc.