A protocol for loading Calcein-AM into extracellular vesicles from mammalian cells for clear visualization with a...

Area of Science:

• Cell Biology
• Biotechnology
• Microscopy

Background:

• Extracellular vesicles (EVs) are vital for intercellular communication and hold potential as biomarkers.
• Current EV visualization methods often require specialized and expensive equipment, limiting accessibility.
• Standardized, affordable techniques for EV analysis are needed in research settings.

Purpose of the Study:

• To adapt a flow cytometry-based protocol for visualizing EVs using epifluorescence microscopy.
• To provide a more accessible method for basic EV analysis and cellular distribution studies.
• To enable researchers to assess EV internalization and guide further experimental decisions.

Main Methods:

• Adapted a Calcein-AM labeling protocol originally for flow cytometry.
• Utilized epifluorescence microscopy coupled with deconvolution for EV visualization.
• Applied the method for basic analysis of EV distribution and cellular uptake.

Main Results:

• Successfully converted a flow cytometry protocol into an epifluorescence microscopy method for EVs.
• Demonstrated the utility of the adapted method for visualizing EV distribution and internalization.
• Provided a practical tool for initial EV characterization in standard laboratories.

Conclusions:

• Epifluorescence microscopy with deconvolution offers a valuable and accessible approach for basic EV visualization.
• This method can facilitate preliminary studies on EV behavior and cellular interactions.
• The technique serves as a useful preliminary step before employing advanced microscopy or assays.