bioRxiv ScienceSearch

Biology subjects

Rossmann, K.

Publications and source records attributed to Rossmann, K..

2 recordsLinked to original sources

Sulfonated rhodamines as impermeable labelling substrates for cell surface protein visualization

Sulfonated rhodamines that endow xanthene dyes with cellular impermeability are presented. We fuse charged sulfonates to red and far-red dyes to obtain Sulfo549 and Sulfo646, respectively, and further link these to SNAP- and Halo-tag substrates for protein self-labelling. Cellular impermeability is validated in live cell imaging experiments in transfected HEK cells and neurons derived from induced pluripotent stem cells (iPSCs). Lastly, we show that Sulfo646 is amenable to STED nanoscopy by recording membranes of SNAP/Halo-surface-labelled human iPSC-derived neuronal axons. We therefore provide an avenue for rendering dyes impermeable for exclusive extracellular visualization via self-labelling protein tags.

biochemistry

Deuterated rhodamines for protein labelling in nanoscopy

Rhodamine molecules are setting benchmarks in fluorescence microscopy. Herein, we report the deuterium (d12) congeners of tetramethyl(silicon)rhodamine, obtained by isotopic labelling of the four methyl groups, which improves photophysical (i.e. brightness, lifetimes) and chemical (i.e. bleaching) properties. We explore this finding for SNAP- and Halo-tag labelling, and highlight enhanced properties in several applications, such as Forster resonance energy transfer, fluorescence activated cell sorting, fluorescence lifetime microscopy and stimulated emission depletion nanoscopy. We envision deuteration as a generalizable concept to improve existing and develop new Chemical Biology Probes.

physiology