Purification of membrane vesicles from Gram-positive bacteria using flow cytometry, after iodixanol density-gradient ultracentrifugation

Membrane vesicles (MVs) play biologically important roles in Gram-positive bacteria, and purification is essential for their study. Although high-performance flow cytometry has the capability to quantify and isolate specific small particles, it has not been examined for MV isolation. In this study, we used high-performance flow cytometry to analyze MV from Gram-positive bacteria, Staphylococcus aureus and Bacillus subtilis, prepared by iodixanol density-gradient ultracentrifugation. Analysis of the quality of MV samples before and after sorting showed that the flow cytometric sorting provided higher purity and uniformity compared to gradient isolation alone. The MV purification method using flow cytometry should prove useful for applications requiring a very high purity of MV samples such as proteomic, metagenomic or lipidomic studies. (C) 2020 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Automated summary

In this study, high-performance flow cytometry was used to analyze membrane vesicles (MVs) from Gram-positive bacteria, Staphylococcus aureus and Bacillus subtilis, showing that flow cytometric sorting provided higher purity and uniformity compared to gradient isolation alone. The MV purification method using flow cytometry should be useful for applications requiring very high purity of MV samples such as proteomic, metagenomic, or lipidomic studies.