Fighting cancer is a major goal of present-day medicine. So far mainly surgery, chemotherapy or radiation therapy are utilized to extinguish cancerous tissue, or at least set limits to it. Interestingly the human immune system has effective potential to fight cancer cells. Typically it reacts on parasitic, viral or bacterial infections. Thereby T-cells help to …
Figure 1 shows the deposition of recombinant DsRed in tobacco cells. Recombinant DsRed carrying a signal peptide and no further targeting signal was constitutively expressed in tobacco. DsRed fluorescence in leaves was observed in vivo in a Leica DM5000 (A) whereas seeds were observed under a Leica SP2 confocal microscope (B’, C’). For electron microscopy (B, …
Time-gated detection, namely, only collecting the fluorescence photons after a time-delay from the excitation events, reduces complexity, cost, and illumination intensity of a stimulated emission depletion (STED) microscope. In the gated continuous-wave- (CW-) STED implementation, the spatial resolution improves with increased time-delay, but the signal-to-noise ratio (SNR) reduces. Thus, in sub-optimal conditions, such as a …
These resolution values, when derived from physical and mathematical assumptions, are theoretical estimates. They assume perfect imaging systems and a light point in a vacuum or a fully homogeneous substrate as the specimen. Naturally, this is never the case in real life, let alone in daily laboratory practice. One particularly serious assumption is that light …
The use of SiR dyes for live-cell imaging requires the specific labeling of a protein of interest. In general, this is achieved by coupling of SiR to targeting ligands. For example, SiR derivatives that specifically react with self-labeling protein tags such as SNAP-, CLIP or Halo-protein tags have been described [1]. The most popular self-labeling protein …
Just about everyone who has examined fluorescent samples under the microscope is aware of the constant struggle to have enough signal to see the labeled structures while also avoiding fluorophore bleaching. What may be less apparent, at least to those who image bright, robust or fixed samples, is how stressful and potentially toxic to living …
Nature Methods: Light-sheet Fluorescence Microscopy – Method of the Year 2014 Read More »
Diffraction plays a crucial role in microscopy as it prevents the recording of arbitrarily sharp images with conventional light microscopes. Many names are connected with the notion of diffraction and the definition of resolution. An overview over the contributions of the different scientists to the recognition and definition of the diffraction barrier in the past …
Audrey Salles is a specialist for confocal and super-resolution microscopy at Pasteur Institute, Imagopole, PFID, Paris, France. Her research interests are cytokine signaling and skeleton organization of human TCD4-cells. Confocal microscopy is really important for her studies: in order to visualize the molecules of her interest in the cytoplasm in sufficient resolution, a really good …
About iBiology iBiology (www.ibiology.org) is a collection of open-access online videos by scientists about research and discoveries that cover a wide variety of life science subjects. iBiology has produced over 80 videos by the world’s leading scientists including seminars about research in fields from ecology to biophysics, a 65-video course on light microscopy, and over …
Video Talk by Jeff Lichtman: Point Spread Function Read More »
In recent years, increasing numbers of human campylobacteriosis cases caused by contaminated water have been reported. As the culture-based detection of Campylobacter is time consuming and can yield false-negative results, the suitability of a quantitative real-time PCR method in combination with an ethidium monoazide pretreatment of samples (EMA-qPCR) for the rapid, quantitative detection of viable …
