1 of 2 Hospital acquired infection that leads to sepsis is deadly, expensive, and increasingly common. Rapid diagnosis, anti-microbial treatment, and identification of the pathogen strain is key to improving outcomes and reducing costs. Diagnosis and strain identification must improve. Novel techniques for blood culture (BC) and molecular diagnostics (MDx) are promising, but better technology for pathogen purification and concentration from blood will be essential for the next generation of diagnostics. We will develop a device to purify and concentrate pathogens directly from a large volume (?10 mL) of whole blood. Unlike existing techniques, our technology will achieve the high binding efficiency of a filter with the non- clogging properties of an empty flow cell.