The development of early and personalized diagnostic protocol with rapid response and high accuracy is considered the most promising avenue to advance point-of-care testing for tumor diagnosis and therapy. Given the growing awareness of the limitations of conventional tissue biopsy for gathering tumor information, considerable interest has recently been aroused in liquid biopsy. Among a myriad of analytical approaches proposed for liquid biopsy, microfluidics-based separation and purification techniques possess merits of high throughput, low samples consumption, high flexibility, low cost, high sensitivity, automation capability and enhanced spatio-temporal control. These characteristics endow microfluidics to serve as an emerging and promising tool in tumor diagnosis and prognosis by identifying specific circulating tumor biomarkers. In this review, we will put our focus on three key categories of circulating tumor biomarkers, namely, circulating tumor cells (CTCs), circulating exosomes, and circulating nucleic acids (cNAs), and discuss the significant roles of microfluidics in the separation and analysis of circulating tumor biomarkers. Recent advances in microfluidic separation and analysis of CTCs, exosomes, and cNAs will be highlighted and tabulated. Finally, the current challenges and future niches of using microfluidic techniques in the separation and analysis of circulating tumor biomarkers will be discussed.

早期开发具有快速响应和高精度的个性化诊断方案被认为是进行肿瘤诊断和治疗的即时检验最有希望的途径。鉴于人们越来越意识到常规组织活检在收集肿瘤信息方面的局限性，最近人们对液体活检引起了极大的兴趣。在针对液体活检提出的众多分析方法中，基于微流体的分离和纯化技术具有高通量，低样品消耗，高灵活性，低成本，高灵敏度，自动化能力和增强的时空控制等优点。这些特征赋予微流控技术以通过鉴定特定的循环肿瘤生物标记物而在肿瘤诊断和预后中成为新兴和有希望的工具的能力。在这篇综述中，我们将把重点放在循环肿瘤生物标记物的三个关键类别上，即循环肿瘤细胞（CTC），循环外来体和循环核酸（cNA），并讨论微流体在分离和分析中的重要作用。循环肿瘤生物标志物。CTC，外来体和cNA的微流控分离和分析的最新进展将被突出并制成表格。最后，将讨论在循环肿瘤生物标志物的分离和分析中使用微流体技术的当前挑战和未来的机遇。并讨论了微流体在循环肿瘤生物标志物分离和分析中的重要作用。CTC，外来体和cNA的微流控分离和分析的最新进展将被突出并制成表格。最后，将讨论在循环肿瘤生物标志物的分离和分析中使用微流体技术的当前挑战和未来的机遇。并讨论了微流体在循环肿瘤生物标志物分离和分析中的重要作用。CTC，外来体和cNA的微流控分离和分析的最新进展将被突出并制成表格。最后，将讨论在循环肿瘤生物标志物的分离和分析中使用微流体技术的当前挑战和未来的机遇。