Figure 3.

Schematic representation comparing exosome isolation strategies using SEC method. In conventional SEC, melanoma cell culture supernatant is harvested and is directly applied to SEC columns. In some cases, when concentration is required, low (3 kD) MWCO ultrafiltration is used to reduce excess water and electrolytes to load the correct volume onto SEC (100 μL). It is assumed that soluble biologics (e.g. cytokines) that remain are an integral part of exosomes. For REIUS method, 100 kD MWCO ultrafiltration is used to reduce soluble factors that are under 100 kD, followed by SEC. This method is proposed to reduce soluble factors more efficiently than SEC alone. For both methods, presence of non-exosomal soluble factors was examined in detail. Portions of this figure were made using templates from Motifolio Scientific Illustration Toolkits (www.motifolio.com).