Abstract: The present invention provides a protocol and apparatus for enriching circulating tumor cells and other rare cells from blood, including debris and other components, from samples with high precision and at high throughput rates. This invention discloses an improved processing system from previously described semi-automated sample processing. The system further reduces operator intervention and hands-on time from prior systems. While this system has general utility in processing diverse materials, the system is configured for sample processing of biological specimens to provide an enriched fraction suitable for detection, enumeration and identification of target cells by appropriate analytical methodologies.