The ability to distinguish and isolate rare cells from among a large population of assorted cells has become increasingly important for the early detection of disease and for monitoring disease treatments. Circulating cancer tumor cells are a perfect example. Typically, there are only a handful of them among a billion healthy cells, yet they are precursors to metastasis, the spread of cancer that causes about 90 percent of cancer mortalities. Such “rogue” cells are not limited to cancer -- they also include stem cells used for regenerative medicine and other cell types.
