Detection of Circulating Tumor Cells by Fluorescence Microspheres-Mediated Amplification

Here we describe a fluorescent microspheres-based separation and analysis that enables the isolation of circulating tumor cells (CTCs) from whole blood of patients with metastatic cancer and the identification of isolated CTCs in situ without immunostaining. This approach uses antibody-functionalized fluorescent polystyrene (PS) microspheres that can selectively bind to CTCs. The binding of CTCs and fluorescent PS microspheres leads to the formation of complexes of CTCs and fluorescent PS microspheres, thereby the CTCs are size-amplified and labeled simultaneously. A pyramidal microcavity array (PMCA) is fabricated using microfabrication technology to create a precise microfilter structure with a high aspect ratio. The PMCA filter device can effectively isolate microspheres-labeled CTCs, while allow hematologic cells to deform and pass through. Using this approach, CTCs are isolated and identified in 15 of 18 patients with metastatic colorectal cancer. This approach will open new possibilities for CTCs isolation and identification and can serve a versatile platform to facilitate CTCs analysis in diverse biomedical applications.