The objective of this project is to deliver a fully integrated CLIA-certified technology that provides diagnostic characterization of individually identified CTC?s harvested from human specimens. We will use a novel patented chip-based dielectrophoretic-controlled isolation process (DEPArray) to identify and isolate single CTCs while maintaining their functional biological integrity. Using this technology we have developed a strategy for classifying CTCs into defined subsets with identifiable characteristics useful for clinical research and diagnosis. The specific tasks for this Phase I contract are to: 1) Establish a robust method for comprehensive detection and isolation of single circulating tumor cells 2) Define and isolate specific subsets of CTCs based on extracellular antigen expression 3) Demonstrate the ability to perform molecular analysis on single cells isolated from subgroups of CTCs 4) Demonstrate reproducibility of an integrated ?CTC Detection, Recovery, and Analysis? system This SBIR contract will enable development of a fully-integrated and robust cell-identification and separation system to support CTC cancer research and diagnostics. This novel technology promises to revolutionize the identification of new subsets of CTCs and also assign clinically useful characteristics, such as metastatic potential, to each subset of cells.