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 λabs of 652 nm and a λem 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?“
Super-resolution imaging techniques operate beyond the limit set by the diffraction of light, leading to new insights in cellular biology. Among these techniques, the direct stochastic optical reconstruction microscopy (dSTORM) approach is based on the use of blinking fluorescent dyes allowing spatial resolution of about 20 nm. This post is focusing on a new type of fluorescent dye compatible with both live-cell imaging and staining of fixed cells adapted to dSTORM.