Imaging fitc-dextran as a reporter for regulated exocytosis

Ofir Klein, Amit Roded, Koret Hirschberg, Mitsunori Fukuda, Stephen J. Galli, Ronit Sagi-Eisenberg*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Regulated exocytosis is a process by which cargo, which is stored in secretory granules (SGs), is released in response to a secretory trigger. Regulated exocytosis is fundamental for intercellular communication and is a key mechanism for the secretion of neurotransmitters, hormones, inflammatory mediators, and other compounds, by a variety of cells. At least three distinct mechanisms are known for regulated exocytosis: full exocytosis, where a single SG fully fuses with the plasma membrane, kiss-and-run exocytosis, where a single SG transiently fuses with the plasma membrane, and compound exocytosis, where several SGs fuse with each other, prior to or after SG fusion with the plasma membrane. The type of regulated exocytosis undertaken by a cell is often dictated by the type of secretory trigger. However, in many cells, a single secretory trigger can activate multiple modes of regulated exocytosis simultaneously. Despite their abundance and importance across cell types and species, the mechanisms that determine the different modes of secretion are largely unresolved. One of the main challenges in investigating the different modes of regulated exocytosis, is the difficulty in distinguishing between them as well as exploring them separately. Here we describe the use of fluorescein isothiocyanate (FITC)-dextran as an exocytosis reporter, and live cell imaging, to differentiate between the different pathways of regulated exocytosis, focusing on compound exocytosis, based on the robustness and duration of the exocytic events.

Original languageEnglish
Article numbere57936
JournalJournal of Visualized Experiments
Issue number136
StatePublished - 20 Jun 2018


FundersFunder number
Israel Academy for Sciences
National Institutes of HealthU19 AI 104209
National Institute of Arthritis and Musculoskeletal and Skin DiseasesR01AR067145
United States-Israel Binational Science Foundation2013263
Israel Science Foundation933/15


    • Biology
    • Compound exocytosis
    • FITC-dextran
    • Issue 136
    • Live cell imaging
    • Lysosome-related organelles
    • Pinocytosis
    • Regulated exocytosis


    Dive into the research topics of 'Imaging fitc-dextran as a reporter for regulated exocytosis'. Together they form a unique fingerprint.

    Cite this