Our current understanding of clinical significance or the lack thereof of circulating tumor cells (CTCs) is biased by the technology used to isolate these rare cells. Despite the presence of a vast number of academic and commercial technologies, the lack of a standardized and optimized platform has been widely noted. We present a negative enrichment approach, integrating WBC depletion and chemical-free RBC depletion in the same setup without the need for centrifugation, washing or multiple sample handling steps. This approach achieves an average of >90 % recovery of spiked tumor cells and >99 % total WBC depletion in whole blood across multiple cell lines, in a simple and easy-to-use assay. The results presented herein and ongoing improvements aim to fulfill the need for a highly reliable, unbiased, standardized, and optimized CTC isolation platform, using component technologies that are validated for cell isolation.