Hi, I stumbled upon this company, who made a simple bloodtest(as they describe it) that captures and assesses CTCs: http://www.veridex.com/CellSearch/CellSearchHCP.aspx At your right-hand side, you'll find a nice movie(CellSearch Movie), where they visualise their CTC-testing. Personally, I think this holds future, by attracting tumor cells to where you want to have it. This principle can be applied to viruses perhaps. Current problem is not so much the sensitivity of the tests, but merely to 'catch' the virus(or tumor cells) to where you want to have it, and test subsequently. Best wishes, OS.