A Microfluidic Chip for Efficient Circulating Tumor Cells Enrichment, Screening, and Single-Cell RNA Sequencing

Single-cell RNA sequencing on circulating tumor cells (CTCs) proves useful to study mechanisms of tumor heterogeneity, metastasis, and drug resistance. Currently, single-cell RNA sequencing of CTCs usually takes three prerequisite steps: enrichment of CTCs from whole blood, characterization of captured cells by immunostaining and microscopic imaging, and single-cell isolation through micromanipulation. However, multiple pipetting and transferring steps can easily cause the loss of rare CTCs. To address this issue, a novel integrated microfluidic chip for sequential enrichment, isolation, and characterization of CTCs at single-cell level, is developed. And, single CTC lysis is achieved on the same chip. The microfluidic chip includes functions of blood clot filtration, single-cell isolation, identification, and target single-cell lysate collection. By spiking tumor cells into whole blood, it is validated that this microfluidic chip can effectively conduct single-cell CTCs RNA sequencing. The approach lays a solid foundation for the analysis of RNA expression profiling of single-cell CTCs.