Advances in exosome quantification techniques

Accumulated evidence has indicated that exosomes play a vital role in many biological processes such as intercellular communication, antigen presentation, and waste management. Since the fingerprints of exosomes resemble their parental cells, they are widely recognized as next generation biomarkers for disease diagnosis, prognosis, and therapy. Being endogenous in nature, exosomes also present themselves as an exquisite vehicle for the delivery of therapeutic cargoes because of their immunological inertness and exceptional ability to elicit potent cellular responses. Therefore, the quantification of exosomes is crucial in facilitating exosome research and applications. In this article, we summarize the progress in exosome quantification techniques with representative examples to illustrate their working principles with some discussion on challenges and prospects. We hope that this article will offer an overview of exosome quantification techniques and open up new avenues towards the development innovative concepts and instruments for exosome research and applications.