Researchers develop a nanosensing platform that can assess the quality of individual viral vector particles Viral vectors hold much potential for gene editing and gene therapy, but there is a pressing need to develop quality control methods to minimize potential side effects on patients. Addressing this, researchers from Japan developed a nanosensing-based approach that can differentiate between functional and faulty viral vectors at the single-particle level. This convenient and inexpensive technique will hopefully get us one step closer to advancing treatments for genetic disorders.