Figure 1. Western Blot Analysis of Lyophilized Extracellular Vesicles (EVs) from Biofluid and Cell Culture Sources Showing Characteristic Tetraspanin Expression

Lyophilized EVs were reconstituted in deionized water to a final concentration of 1 µg/µL and loaded based on the indicated µg amount below each blot. Blots were run under non-reducing conditions and probed for EV-associated markers using the Extracellular Vesicle Human CD9/CD63/CD81 Antibody Panel, with albumin included as a non-EV protein control. (A) EVs derived from human biofluids (plasma, serum, and urine) and (B) EVs derived from cultured cell lines (HEK293, A549, HCT116, and HT29) are shown. All samples exhibit typical tetraspanin expression, with albumin levels significantly reduced across EVs from biofluids, most notably plasma and urine, and no detectable albumin signal in EVs from cell culture sources.