Detection of single tumor cell resistance with aptamer biochip.

In this study, a novel RNA aptamer biochip was developed for tumor cell capture and detection of single cell resistance. This biochip consists of a polydimethylsiloxane (PDMS) cover containing a channel for introducing cells and sustaining their activity and microelectrode matrix on a silicon dioxide layer. Epidermal growth factor receptor (EGFR) aptamers which specifically identify and isolate tumor cells were attached in the gap between two electrodes. After cell biochip incubation, surplus tumor cells were removed, and those dwelling on the intervals were further analyzed. When resistance measurement was completed, these cells were flushed away via controlled flow acceleration, and were collected for further analysis. The results demonstrate the convenience and efficiency of using anti-EGFR aptamer biochips for the detection of single cell resistance. This novel aptamer biochip may be used for the isolation of circulating tumor cells from peripheral blood and cell counting, or be assembled with other lab-on-a-chip components for follow-up gene and protein analysis.