Membrane vesicles in freshwater ecosystems: Quantification by flow cytometry and interferometric microscopy

Abstract

Membrane vesicles (MVs) are produced by cells from all domains of life and could be involved in the horizontal gene transfer (HGT). They were found in some environments as seawater and rivers but technological improvements must be required to found out their roles in the ecosystems. In this work, we developed a method using flow cytometry (FC) after lipid staining dye FM4-64 and compared the results to those obtained with Interferometric Microscopy (IM). The abundance of nanoparticles in different lakes determined by the two methods were in agreement. Moreover, nanoparticles with a high refraction index were particularly abundant suggesting that MVs could be associated with several virus particles or to very dense compounds such as iron oxides.