Neuronal polarity is essential for the proper development, growth, and physiology of neurons. Within neurons, microtubules (MTs) and motor protein polarities are required for establishing and maintaining neuronal polarity. However, unanswered questions remain: 1. Why are some cytoplasmic molecules in axons but not dendrites? 2. How do MAPs become compartmentalized differently in each type of neurite? 3. Why does a neuron have a single axon but multiple dendrites?⁵

To help you, the researcher, to answer these questions (as well as many others regarding MT functions in the central nervous system!) for a number of years now we’ve been providing a reliable range of kits by Cytoskeleton Inc. Their highly useful reagents include the Signal-Seeker Enrichment kits for quantifying levels of endogenous PTMs such as acetylation, tyrosine phosphorylation, ubiquitination, and SUMOylation, as well as purified cytoskeletal proteins (e.g., actins, tubulins, kinesin and dynein motors) and functional assay kits to measure the activities of these same proteins.

The ubiquitin-proteasome system (UPS) is a well-characterized protein degradation system in cells whose dysfunction is implicated in many diseases, including neurodegeneration and cancer^1,2. Major UPS components are ubiquitin (Ub), Ub ligases, Ub hydrolases (deubiquitinases [DUBs]), and the proteasome.

For more than 2 years now, the Silicon Rhodamine-like (SiR) technology has allowed the live cell imaging field with fluorescence microscopy to evolve significantly.

Fluorescent SiR-probes have appeared as the best alternative tools for studying Actin (SiR-actin), Microtubules (SiR-Tubulin), DNA (SiR-DNA) and now lysosome (SiR-Lysosome) for live cell imaging. Who better to show this? Well, here’s how other researchers have been using them to get optimal results.

The Silicon Rhodamine-like (SiR) technology has significantly contributed to the recent development of DNA and cytoskeletal analysis by live cell imaging.

In 2014, two new Silicon Rhodamine-like (SiR) fluorescent probes were released for studying actin & tubulin by live cell imaging. SiR-Actin and SiR-Tubulin are fluorescent probes compatible with most microscopes (including super-resolution settings) that directly stain actin & tubulin without the need to transfect cells with vectors expressing fluorescently labeled Actin or Tubulin. The two original dyes were successfully followed by a new SiR-DNA probe in order to visualize DNA in living cells.

The existing SiR stains have a λ_abs of 652 nm and a λ_em of 674 nm to be used with the Cy5 filter (Fig 1).

However, the continuously growing number of researchers using these stains asked us whether stains with different biophysical properties would be made available. In other words, they were asking “is there another colour to allow for double staining e.g. of Actin and Tubulin in living cells?“