NOTE: We recommend using serum-free media to avoid concentration of overly abundant albumin that is present in Fetal Bovine Serum (FBS). If albumin is not a concern, the protocol may be used on serum-containing samples. To achieve similar concentration, centrifugation times must be lengthened (Steps 9 and 11, below) due to increased protein content.
NOTE: FBS also contains exosomes, which may interfere with certain downstream analyses. Exosome-free media, such as Exo-FBS™ Exosome depleted media (System Biosciences), will still contain albumin.