SpyRho 555 is a fluorogenic dye ligand for the RNA aptamer RhoBAST developed by the lab of Murat Sunbul in Heidelberg University1). SpyRho 555 is a rhodamine dye that is cell permeable, highly fluorogenic and photostable. With its high affinity and fast on/off binding kinetics to its cognate aptamer RhoBAST, it allows overcoming the main issues of live cell RNA imaging. SpyRho 555 is highly suited for widefield, confocal, STED or single molecule localization microscopy in a PAINT like setup.
SpyRho 555 enables multicolor imaging with SPY505, SPY595, SPY650, SPY700, SiR and GFP. SpyRho 555 can be imaged with standard TMR or Cy3 settings. Probe quantity allows 100 staining experiments.*
Figure 1. A Chemical structure of SpyRho 555. B SpyRho 555 reversibly binds to RhoBAST aptamer with fast kinetics. Unbound SpyRho 555 exists predominantly in the closed form and is not fluorescent. Upon binding to RhoBAST aptamer, SpyRho 555 switches to the open form and becomes highly fluorescent.
|Absorbance maximum λabs||562 nm|
|Fluorescence maximum λfl||581 nm|
|Works on fixed cells?||Yes|
|Probe quantity||100 stainings*|
|Fluorescence quantum yield (RNA bound)||0.95|
|Kd to RhoBAST aptamer||34 nM|
|STED depletion wavelength||660 nm|
*Based on the following conditions: 0.5 ml staining solution / staining experiment with 1x probe concentration. The number of staining experiments can be further increased by reducing the staining solution volume or the probe concentration.
1. Daniel Englert et al. Fast-exchanging spirocyclic rhodamine probes for aptamer-based super-resolution RNA imaging” bioRxiv 2022.10.24.513449 https://doi.org/10.1101/2022.10.24.513449