Isolation of EVs from DLBCL cell lines and primary sample. (A) Size distribution and concentration of EVs isolated from OCI-Ly1 cell line (top) and a primary DLBCL sample of GCB subtype (bottom) by ultracentrifugation determined by the NanoSight instrument. (B) Western blot for the exosomal proteins ALIX (100 kDa), TSG101 (46 kDa), CD81 (26 kDa), and as a negative control, HSP90B1 protein (90 kDa). (C) FACS analysis of exosomal surface markers demonstrates expression of CD63 in OCI-Ly1–derived EVs but not in the parental whole cells, expression of B-cell surface marker CD20, GC marker CD10, but not T-cell marker CD4 in both derived EVs and parental OCI-Ly1 cells. (D) Confocal fluorescence microscope image shows uptake of EVs released by lymphoma OCI-LY1 cells (green) by stromal HK cells (blue = DAPI; red = α-actin).