Page 2 Drug and Gene Targeting Efficient Delivery of Agents to Molecular Targets in vitro assays ranging from well-defined ligand binding assays, which include a high throughput robotic screen, to the more complex biological cell-based assays to mimic the in vivo lectin-carbohydrate interactions . The success with this combination of assays has been demonstrated by our discovery of glycomimetics for E-selectin which are 200-fold more active than the native carbohydrate ligand with a 10% reduction in molecular weight. Due to our success and technology in the selectin area, we modified our biological flow assays to initiate our research in targeting. This approach to use selectins as the model of lectin-carbohydrate interactions may lead to a viable clinical applications for using selectins in targeting but also will develop the tools and validate the concept of using lectin-carbohydrate recognition for targeting. The benefit of using biological flow assays to study targeting is to allow direct visualization of the lectin-carbohydrate recognition event of the targeted agent, without artifacts of non-specific protein-protein interactions. Direct visualization is conducted in our video microscopy/ digital imaging laboratory depicted below. Our inverted stage microscope has a large working distance and is equipped with bright field, phase contrast, and epifluorescent optics allowing flexibility in selection of assay format and optical mode to obtain the best visualization of targeting events. Assays dependent on direct visualization to record results can be quite subjective by different individuals, so we utilize digital imaging to standardize and quantify the targeting assays