Instant Exosomes™ are a range of high-quality and well characterized freeze-dried exosome samples from human cancer cell lines. Exosomes are isolated following a combination of precipitation and size exclusion chromatography (SEC). The exosome samples are characterized for overall protein content, using a BCA assay, expression of commonly expressed exosomal markers (CD9, CD63 and CD81) using the ExoLISA™ exosome detection assay and, particle concentration and size distribution by nanoparticle tracking analysis (NTA) using a Zetaview® instrument from Particle Metrix GmbH.