“…Thef irst methods developed for CTC analysis were designed to facilitate the identification of these cells via immunostaining,b ut the use of destructive characterization was quickly recognized as ac onstraint that would limit downstream analysis of the genetics and proteomics of these cells.Releasing viable cells allows for further analysis such as quantitative PCR, whole genome sequencing,a nd xenograft studies, [54,63,64] which are essential for fully understanding cancer metastases.T his has prompted as earch for gentle conditions that could be used to release fragile CTCs from capture devices.O ver the last several years,av ariety of systems have permitted the efficient recovery of cancer cells after capture by using chemical, [65] enzymatic, [66,67] selfassembly, [68] mechanosensitive, [69] and thermal release [70,71] mechanisms (Figure 4). High levels of cellular viability have been achieved for cancer cells isolated with low levels of contaminating cells.This is anew capability that will enhance our understanding of the biological properties of CTCs and their medical relevance.…”