Genetically-encoded markers for confocal visualization of single dense core vesicles.

Neuronal dense core vesicles (DCVs) store and release a diverse array of neuromodulators, trophic factors, and bioamines. The analysis of single DCVs has largely been possible only using electron microscopy, which makes understanding cargo segregation and DCV heterogeneity difficult. To address these limitations, we develop genetically encoded markers for DCVs that can be used in combination with standard immunohistochemistry and expansion microscopy to enable single-vesicle resolution with confocal microscopy in Drosophila.