Rare cell isolation and recovery on open-channel microfluidic chip.

The ability to accurately detect and analyze rare cells in a cell population is critical not only for the study of disease progression but also for next flow cytometry systems in clinical application. Here, we report the development of a prototype device, the 'Rare cell sorter', for isolating and recovering single rare cells from whole blood samples. On this device, we utilized an open-channel microfluidic chip for rare cell isolation. And the advantage of open-channel allows us to recover the isolated rare cell directly from the chip. We set the circulating tumor cell (CTC) as a target cell. For the clinical experiment, CTCs were isolated from blood samples collected from patients with metastatic breast cancer and healthy volunteers. There was a significant difference in the number of CTCs between the patients with metastatic breast cancer and healthy volunteers. To evaluate the damage to cells during isolation and recovery, we performed an RNA integrity assay using RNA extracted from CTCs recovered from the chip and found that our process for single CTC isolation and recovery is mild enough for gene analysis of CTCs.