Super-Resolution Imaging of the Golgi in Live Cells with a Bioorthogonal Ceramide Probe

We report a lipid-based strategy to visualize Golgi structure and dynamics at super-resolution in live cells. The method is based on two novel reagents: a trans-cyclooctene-containing ceramide lipid (Cer-TCO) and a highly reactive, tetrazine-tagged near-IR dye (SiR-Tz). These reagents assemble via an extremely rapid tetrazine-click reaction into Cer-SiR, a highly photostable vital dye that enables prolonged live-cell imaging of the Golgi apparatus by 3D confocal and STED microscopy. Cer-SiR is nontoxic at concentrations as high as 2 mu m and does not perturb the mobility of Golgi-resident enzymes or the traffic of cargo from the endoplasmic reticulum through the Golgi and to the plasma membrane.