Immunofluorescent Innovations and Applications
More specific fluorescent tags
IBA’s new multimer Streptamer® reagents are a boon to researchers studying T-cells of the immune system. “The Strep-tag is a very commonly used tag in the field of recombinant protein production,” says Gisela Mäck, product manager for Cell TAGnologies at IBA. “Due to its advantages based on its highly specific binding properties and the mild elution conditions, it allows the isolation of highly pure proteins and even protein complexes in one step. The newly offered, fluorescently conjugated monoclonal antibodies against the Strep-tag® represent an extension of the existing portfolio for recombinant protein production. With these directly conjugated antibodies, the customer can further analyze the already Strep-tagged protein in vivo and also protein interactions in protein complexes.”
IBA has also incorporated its Strep-tag® technology into two assays for apoptosis. The transmembrane protein FasL (or CD95L), expressed in the cell membranes of T cells, is known to be important for regulating normal B and T cell function, among many other crucial immune functions. FasL is thought to form a homotrimer before binding the Fas receptor, thereby triggering apoptosis through caspase activation. IBA’s new tool is the FasL-Strep molecule, which includes a Strep-tag® for immunofluorescent detection. It is used in two new apoptosis assays.
Indeed, translating apoptosis tools into cancer treatments—a lofty goal—remains a little way off. In the meantime, taking advantage of molecular tools, such as immunofluorescent tags, to help scientists discover where individual molecules are acting, and who they are forming binding complexes with, is an active area of research. “In my opinion, the biggest challenges in the field of immunofluorescence will emerge from science in order to understand and therefore visualize biological processes in more and more detail, such as single molecule analysis,” says Mäck. In order to study smaller and smaller units of biological processes, though, detection technologies must continue to progress as well. “To fulfill this demand,” says Mäck, “dye companies will have to develop, on the one hand, increasingly sensitive and stable dyes to detect even weak signals; and on the other hand, optical systems are needed for the detection of these dyes.” For example, she notes new developments in FRET (fluorescence resonance energy transfer) technology for detecting protein-protein interactions, and in ChIP (chromatin immunoprecipitation) technology for detecting DNA-protein interactions. “The screening and verification of complex protein-protein and DNA-protein interactions within biological processes will be a major field of investigation in the future,” Mäck predicts.
