检测腹水和腹腔冲洗液中的游离癌细胞对胃癌（GC）的诊断至关重要。然而，传统方法在早期诊断方面的灵敏度较低。我们开发了一种无标记、快速、高通量的技术，利用集成微流体器件，采用迪恩流分离和确定性侧向位移，从腹水和腹腔冲洗液中分离癌细胞。随后，使用微流体单细胞捕获阵列芯片（SCTA芯片）分析分离的细胞。对SCTA芯片中的细胞进行EpCAM、YAP-1、HER-2、CD45分子表达的原位免疫荧光以及Wright-Giemsa染色。最后，使用免疫组化分析组织中的YAP1和HER-2表达情况。通过集成微流体器件，我们成功地从含1/10,000癌细胞的模拟腹腔冲洗液中分离出癌细胞，恢复率为84.8%，纯度为72.4%。随后，从12名患者的腹水样本中分离出癌细胞。细胞学检查显示，背景细胞被排除，癌细胞被有效富集。随后，对来自腹水的分离细胞进行了SCTA芯片分析，并通过EpCAM+/CD45-表达和Wright-Giemsa染色识别为癌细胞。有趣的是，12个腹水样本中的8个呈现出HER-2+癌细胞。最后，通过一系列表达分析结果显示，在转移过程中YAP1和HER-2的表达不一致。我们研发的微流体芯片不仅可以快速、高通量地检测腹水和腹腔冲洗液中无标记的GC细胞，还可以对腹水癌细胞进行单细胞水平的分析，提高腹膜转移癌的诊断以及治疗靶点的研究。本研究得到中国国家自然科学基金（22134004，U1908207，91859111）、山东省自然科学基金（ZR2019JQ06）、山东省泰山学者计划（tsqn201909077）、中央政府引导的地方科技发展基金（YDZX20203700002568）以及辽宁省应用基础研究计划（2022020284-JH2/1013）的支持。版权所有 © 2023 The Author(s)，Elsevier B.V.保留所有权利。

Detecting free cancer cells from ascites and peritoneal lavages is crucial for diagnosing gastric cancer (GC). However, traditional methods are limited for early-stage diagnosis due to their low sensitivity.A label-free, rapid, and high-throughput technique was developed for separating cancer cells from ascites and peritoneal lavages using an integrated microfluidic device, taking advantage of dean flow fractionation and deterministic lateral displacement. Afterward, separated cells were analyzed using a microfluidic single-cell trapping array chip (SCTA-chip). In situ immunofluorescence for EpCAM, YAP-1, HER-2, CD45 molecular expressions, and Wright-Giemsa staining were performed for cells in SCTA-chips. At last, YAP1 and HER-2 expression in tissues was analyzed by immunohistochemistry.Through integrated microfluidic device, cancer cells were successfully separated from simulated peritoneal lavages containing 1/10,000 cancer cells with recovery rate of 84.8% and purity of 72.4%. Afterward, cancer cells were isolated from 12 patients' ascites samples. Cytological examinations showed cancer cells were efficiently enriched with background cells excluded. Afterwards, separated cells from ascites were analyzed by SCTA-chips, and recognized as cancer cells through EpCAM+/CD45- expression and Wright-Giemsa staining. Interestingly, 8 out of 12 ascites samples showed HER-2+ cancer cells. At last, the results through a serial expression analysis showed that YAP1 and HER-2 have discordant expression during metastasis.Microfluidic Chips developed in our study could not only rapidly detect label-free free GC cells in ascites and peritoneal lavages with high-throughput, they could also analyze ascites cancer cells at the single-cell level, improving peritoneal metastasis diagnosis and investigation of therapeutic targets.This research was supported by National Natural Science Foundation of China (22134004, U1908207, 91859111); Natural Science Foundation of Shandong Province of China (ZR2019JQ06); Taishan Scholars Program of Shandong Province tsqn (201909077); Local Science and Technology Development Fund Guided by the Central Government (YDZX20203700002568); Applied Basic Research Program of Liaoning Province (2022020284-JH2/1013).Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.