Exosomes are a subset of extracellular vesicles released from various cells, and they can be found in different bodily fluids. Exosomes are used as biomarkers to diagnose many diseases and to monitor therapy efficiency as they represent the status and origin of the cell, which they are released from. Considering that they co-exist in bodily fluids with other types of particles, their isolation still remains challenging since conventional separation methods are time-consuming, user-dependent, and result in low isolation yield. This review summarizes the conventional strategies and microfluidic-based methods for exosome isolation along with their strengths and limitations. Microfluidic devices emerge as a promising approach to overcome the limitations of the conventional methods due to their inherent characteristics, such as the need for minute sample volume and rapid operation, in order to isolate exosomes with a high yield and a high purity in a short amount of time, which make them unprecedented tools for molecular biology and clinical applications. This review elaborates on the existing microfluidic-based exosome isolation methods and denotes their benefits and drawbacks. Herein, we also introduce various commercially available platforms and kits for exosome isolation along with their working principles.

外泌体是从各种细胞释放的细胞外囊泡的一个子集，它们可以在不同的体液中找到。外泌体被用作诊断许多疾病和监测治疗效率的生物标志物，因为它们代表了释放它们的细胞的状态和起源。考虑到它们与其他类型的颗粒共存于体液中，它们的分离仍然具有挑战性，因为传统的分离方法耗时、依赖于用户并且导致分离率低。本综述总结了用于外泌体分离的常规策略和基于微流体的方法及其优势和局限性。微流体装置因其固有的特性而成为克服传统方法局限性的有前途的方法，例如需要极少的样本量和快速操作，以便在短时间内以高产率和高纯度分离外泌体，这使其成为分子生物学和临床应用的前所未有的工具。本综述详细阐述了现有的基于微流体的外泌体分离方法，并指出了它们的优缺点。在此，我们还介绍了用于外泌体分离的各种市售平台和试剂盒及其工作原理。