Blinking fluorescent probes for tubulin nanoscopy in living and fixed cells

Here we report a small molecule probe for single molecule localisation microscopy (SMLM) of tubulin in living and fixed cells. We explored a series of constructs composed of taxanes and spontaneously blinking far-red dye hydroxymethyl silicon-rhodamine (HMSiR). We found that the linker length profoundly affects the probe permeability and off-targeting. The best performing probe, HMSiR-tubulin, is composed of cabazitaxel and 6'-regioisomer of HMSiR bridged by a C6 linker. Microtubule diameters of <50 nm can be routinely measured in SMLM experiments on living and fixed cells. HMSiR-tubulin also performs well in 3D stimulated emission depletion (STED) microscopy, allowing a complementary use of both nanoscopy methods for investigating microtubule functions in living cells.

Inhibition of efflux pumps aids small-molecule probe-based fluorescence labeling and imaging in the gram-negative bacterium Escherichia coli

A major challenge in fluorescence imaging experiments, which are essential to determine protein activity, expression, and localization, is the penetration of small-molecule probes through the outer membrane permeability barrier of...

A platinum(II)-napthalimide probe for sub-cellular imaging of bacteria

There is a lack of molecular probes for imaging bacteria, in comparison to the array of such tools available for the imaging of mammalian cells. A platinum(II)-naphthalimide molecule has been developed as a small molecule probe for bacterial imaging, designed to have the potential for correlative imaging. The naphthalimide moiety acts as a luminescent probe for super-resolution microscopy, functioning independently of the platinum(II) centre which enabled visualisation of the complex with ion nanoscopy. Structured illumination microscopy (SIM) imaging on live <i>Bacillus cereus</i> confirmed the suitability of the probe for super-resolution microscopy. NanoSIMS analysis was used to monitor the uptake of the platinum(II) complex within the bacteria and proved the multimodal action of the probe. The successful combination of these two probe moieties introduces a platform that could lead to a versatile range of correlative probes for bacteria.<br>

A platinum(II)-napthalimide probe for sub-cellular imaging of bacteria

There is a lack of molecular probes for imaging bacteria, in comparison to the array of such tools available for the imaging of mammalian cells. A platinum(II)-naphthalimide molecule has been developed as a small molecule probe for bacterial imaging, designed to have the potential for correlative imaging. The naphthalimide moiety acts as a luminescent probe for super-resolution microscopy, functioning independently of the platinum(II) centre which enabled visualisation of the complex with ion nanoscopy. Structured illumination microscopy (SIM) imaging on live <i>Bacillus cereus</i> confirmed the suitability of the probe for super-resolution microscopy. NanoSIMS analysis was used to monitor the uptake of the platinum(II) complex within the bacteria and proved the multimodal action of the probe. The successful combination of these two probe moieties introduces a platform that could lead to a versatile range of correlative probes for bacteria.<br>