Combination of Immunomagnetic Separation with Aptamer-Mediated Double Rolling Circle Amplification for Highly Sensitive Circulating Tumor Cell Detection

• DOI: 10.1021/acssensors.0c01082
• Publication Date: 2020-11-18T21:10:38Z
• Authors: Shujuan Sun; Shulin Yang; Xuemei Hu; Cheng Zheng; Huanxia Song; Lisha Wang; Zhifa Shen; Zai-Sheng Wu
• Keywords: Aptamer; Circulating tumor cell; Immunomagnetic separation; Rolling circle replication

Breast cancer is the most frequently diagnosed among women, and circulating tumor cell (CTC)-meditated distant metastasis leading cause of death. Thus, detection CTCs great importance for early diagnosis breast prevention metastasis. In this study, using human carcinoma BT474 cells as model CTCs, a powerful assay platform demonstrated by fluorescence spectrometry highly sensitive CTC combining dual-recognizing elements receptor-binding antibody aptamer-mediated separation with double rolling circle amplification reactions (d-RCA, including RCA1 RCA2). The aptamer-inserted product (RCA1-p) exhibits considerably improved affinity towards target originating from multivalent binding effect. immunomagnetic removes nontarget coexisting in complex biological milieu, while centrifugal cells/DNAs mixture eliminates excess probes, thereby circumventing unwanted interferences. spectrometric results show that 34-fold enhanced signal achieved upon cells, can be quantitatively detected down to 9 cells/200 μL linear range five orders magnitude, indicating significantly performance. Even if are spiked fresh whole blood, no obvious fluctuation detected, demonstrating newly developed d-RCA system suitable screening environments expected promising tool estimating predicting recurrence tumors.