Q & A Biorepository Services Will we be able to download the presentation? This presentation will be available to watch on demand on the ATCC website, or click here. How can I quantify the efficiency of angiogenesis? Most researchers quantify the efficiency of angiogenesis using the endothelial cell tube length and number per square millimeter. Imaging software such as ImageJ software or similar can be used to quantify tube formation. For high content screening, there is automated image acquisition and analysis software available from different vendors. Can the cells in the Angio-Ready™ Angiogenesis Assay System (ATCC® ACS-2001-2™ and ACS-2001-10™) be propagated in culture? No, the Angio-Ready™ cells are recommended for a one-time use and should not be subcultured. What markers of endothelial cells have been observed in Angio-Ready™? Expression of CD31 and von Willebrand factor have been observed. Once the VEGF supplement has been added to the Angio-Ready™ Angiogenesis Medium (ATCC® ACS-2008™), how long can I use it? Stored in the refrigerator it is stable for a month. Longer term storage should be at -20oC in single-use volumes. Can you obtain the results of the angiogenesis assay before day 7? Complete tubule development is achieved at 7 days, but depending on what you are looking for the results could be read at any time point. Some researchers obtain their data after 3 days. Remember that live imaging is possible, so the assay can be read multiple times during the assay time frame. For the VEGF dose-dependent assay, why did you observe tubular formation when VEGF concentration is 0? We believe reason could be either that the mesenchymal stem cell component of Angio-Ready™ secreted enough VEGF to support some tubular growth, or that a VEGF-independent pathway contributed to the tubular formation. How did you create the low O2 environment in the hypoxia experiments? The hypoxic condition was created by the over-confluent mesenchymal stem cells. In those experiments the MSC feeder layer was very confluent by the time the endothelial tubules are forming, which created local hypoxia. This system may be similar to the hypoxic microenvironment that is observed in solid tumors.