Alkyne-Tag Raman Imaging
for Visualization of Mobile
Small Molecules in Live Cells
- Publication date
- Publisher
Abstract
Alkyne has a unique Raman band that does not overlap
with Raman
scattering from any endogenous molecule in live cells. Here, we show
that alkyne-tag Raman imaging (ATRI) is a promising approach for visualizing
nonimmobilized small molecules in live cells. An examination of structure–Raman
shift/intensity relationships revealed that alkynes conjugated to
an aromatic ring and/or to a second alkyne (conjugated diynes) have
strong Raman signals in the cellular silent region and can be excellent
tags. Using these design guidelines, we synthesized and imaged a series
of alkyne-tagged coenzyme Q (CoQ) analogues in live cells. Cellular
concentrations of diyne-tagged CoQ analogues could be semiquantitatively
estimated. Finally, simultaneous imaging of two small molecules, 5-ethynyl-2′-deoxyuridine
(EdU) and a CoQ analogue, with distinct Raman tags was demonstrated