How can I analyze proteins from exosomes and other extracellular vesicles (EVs) obtained with the exoEasy Maxi Kit by SDS-PAGE?

To perform SDS-PAGE, just add Laemmli buffer directly to the eluates. There is no need to perform a buffer exchange. Protein concentration in the Buffer XE eluates can be determined using the BCA protein assay without any modification (no additional vesicle lysis required).