Wash-free instant detection of giant plasma membrane vesicles.

Giant plasma membrane vesicles (GPMVs) are large extracellular vesicles produced by the exposure of cells to paraformaldehyde or other stresses, providing an experimental system to elucidate cell surface dynamics. Here we show that addition of the membrane permeable fluorescent RNA-indicators, acridine orange and thioflavin T, to GPMV-containing solutions prepared from cultured HeLa cells was sufficient for the fluorescent visualization of seemingly all GPMVs. Our findings provide a wash-free instant method using non-lipid-type fluorescent dyes for GPMV detection, which should be useful for researchers interested in studying cell membrane dynamics and biochemistry using GPMVs.