Circulating tumor cells (CTCs) can be detected in all solid tumors and are shed into the blood stream early on. Since they can be rare (e.g. 1 CTC in 10 billion blood cells) and quite heterogenous (reflecting the significant heterogeneity of the cells within a tumor of the same patient), it is a challenge to detect and analyze all of them in a given blood sample. CTCs have the advantage that the information (protein, RNA, DNA) of the different CTC-phenotypes are not mixed with others but are contained. Therefore, changes within the mixture of phenotypes during therapy can be easier detected.

Before developing the technology, current principles of CTC isolation/capture were thoroughly studied using standardized assays. As a result, none of the currently used isolation principles could demonstrate to reliably isolate all spiked cells in given blood samples. Consequently, a new technology had to be developed.

• All CTCs can be detected from a give blood sample
• Isolation of CTCs as single cells possible
• Analysis of several genomic and protein markers of the same CTC possible
• Recovery yield of white blood cells (WBCs) > 95% enabling analysis of certain rare WBCs