This reagent is used as anterograde tracer element for pathway analysis in neuronal tissues. bioWORLD producesBiotinylated Dextran Amine (BDA) of approximately 10,000 MW which is conjugated with either fluorescein or Texas Red. These tracer complexes can be introduced effectively in cells by iontophoretic or pressure injection. The anterograde pathway can be traced from the injection site with the fluorescent microscope while cellular details of labeled fibers and terminals can be observed following Avidin/Streptavidin-HRP and a suitable substrate. Furthermore, these modified dextrans can be used in double labeling studies in conjunction with anterograde or retrogradeHRP labeled molecules.