posted on 2015-12-17, 06:26authored byYong Wang, En Cai, Tobias Rosenkranz, Pinghua Ge, Kai Wen Teng, Sung Jun Lim, Andrew
M. Smith, Hee Jung Chung, Frederick Sachs, William N. Green, Philip Gottlieb, Paul R. Selvin
Immunofluorescence,
a powerful technique to detect specific targets
using fluorescently labeled antibodies, has been widely used in both
scientific research and clinical diagnostics. The probes should be
made with small antibodies and high brightness. We conjugated GFP
binding protein (GBP) nanobodies, small single-chain antibodies from
llamas, with new ∼7 nm quantum dots. These provide simple and
versatile immunofluorescence nanoprobes with nanometer accuracy and
resolution. Using the new probes we tracked the walking of individual
kinesin motors and measured their 8 nm step sizes; we tracked Piezo1
channels, which are eukaryotic mechanosensitive channels; we also
tracked AMPA receptors on living neurons. Finally, we used a new super-resolution
algorithm based on blinking of (small) quantum dots that allowed ∼2
nm precision.