While the clinical utility of circulating tumor cells (CTCs) for the management of many different types of cancers are being realized, the challenge in selecting them from peripheral blood and enumerating them is daunting due to the exceedingly high numbers of spectator cells (erythrocytes and leukocytes) and the low abundance of the CTCs (go%. The cartridge will also enumerate the selected CTCs using a non-labeling process that requires no optical equipment;enumeration is accomplished using a conductivity sensor comprised of a pair of electrodes situated orthogonal to the output channel of the device that provides nearly 100% sampling and detection efficiency. The cartridge will also direct the CTCs into a small chamber, stain the cells with antibodies labeled with a fluorescent dye and characterize them using fluorescence microscopy without scanning. The fluidic cartridge will possess a footprint the sue of a microscope slide.