Circulating Tunor Cell (CTC) cell serach by veridex.
basically they can count the number cancer cells circulating in your blood, any thing less than 5 is considered negative. The technique uses monoclonal antibodies for about 5 different common cancer cell types that are tagged so they glow in the dark. Then they use an instrument called flow cytometer to count any cells that have the antibody attached. Here is a link. At the moment it is only approved for monitoring metastic patients. My Onc hopes that will changes as he thinks the test is extremely useful.
http://www.veridex.com/Systems/Systems.aspx?id=1
Kay