In a recent publication, researchers from the University of Miami Miller School of Medicine (USA) describe that Serotonin released by human beta cell inhibits glucagon secretion by alpha cells. They demonstrated that this paracrine loop was mediated via the cAMP pathway. To do so, they captured in live human pancreatic islet cells cAMP signals using a specific fluorescent biosensor.
Understanding how mammalian cells function requires a dynamic perspective. Recent improvements in our abilities to perform fluorescence microscopy on primary cells, coupled with advances in pipelines for quantifying and extracting data, have made possible a better understanding of the temporal complexity of cell signalling pathway. Due to the heterogeneity seen in both eukaryotic and prokaryotic cell populations, study at the single cell resolution with living cells is currently the best solution to understand the dynamics between environmental conditions and cellular behaviour.
However as living cells don’t stay still, classical imaging and studying methods present some drawbacks for single cell analysis and tracking such as: [Read more…]
For more than 2 years now, the Silicon Rhodamine-like (SiR) technology has allowed the live cell imaging field 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. [Read more…]
Reactive oxygen species (ROS) play key roles in various intracellular processes and have been shown to be involved in many diseases (eg. carcinogenesis, inflammation…). Each of the ROS species is likely to have a specific role in living cells. Therefore, there is an emerging need for selectively detecting each species of ROS through conventional biochemical assays, but also in live cell imaging (see a previous post “Reactive Oxygen Species (ROS) and related assay kits“).
The detection of molecular events in living cells is booming. In this post, we look at 3 fluorescent probes that will undoubtedly count in the live-cell imaging landscape in 2017.
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. [Read more…]