Girijesh K Patel

Size distribution and Polydispersity index (PDI) analysis of using dynamic light scattering. To determine the size distribution, freshly isolated exosomes were subjected to dynamic light scattering measurements using DelsaMax Pro (Backman Coulter Inc.). Exosomes isolated using Ultracentrifugation, 101Bio (PureExo), MagCapture and iZON gel-filtration, were under the size range (<150 nm), while the exosomes isolated from Invitrogen precipitation method showed broader size distribution with a shift towards the bigger size.

Exosomes have received significant attention for their role in pathobiological processes and are being explored as a tool for disease diagnosis and management. Consequently, various isolation methods based on different principles have been developed for exosome isolation. Here we compared the efficacy of four kits from Invitrogen.

size distribution, freshly isolated exosomes from different methods were subjected to dynamic light scattering measurements, DelsaMax Pro (Beckman Coulter, Indianapolis, IN, USA). All the exosome preparations from different isolation methods showed the accepted size range (<150 nm) except those resulting from Invitrogen exosomes isolation method (Fig. 2). The latter showed a broad size distribution with a shift towards overall average bigger size (182 ± 13.92 nm). Furthermore, PD index of exosome prep (3 × 10 6 ) were cultured in regular media, after 24 h, media was replaced with 5% exosome depleted FBS. After 48 h condition media was collected, centrifuged at 300 × g for 10 min to.

Even though all of the aforementioned protocols lead to exosome isolation and purification, different types of exosome isolation kits offer different amounts of exosomes and different dispersion stability. Therefore, these variations reduce reproducibility between measurements and cause inconsistency when it comes to result comparison from different laboratories [35,36]. Exosome purification is a sensitive process and the results may be influenced by debris, bacterial flora and various types of sample harvesting (e.g. ...
... miR-200a favors tumor invasion, metastasis and resistance to cancer therapy. Being classified as a tumor-suppressor miR that preserves epithelial phenotype, miR-200a inhibits EMT, tumor invasion and metastasis generation [36,58,59]. Consequently, the downregulation of miR-200a permits EMT and negatively influences host response against tumor expansion, and thus, it can be used as a marker of malignant transformation and invasion [23,60].