Figure 4: Analysis of secretion. (A) HPLC fractionation of CMSC3A1 conditioned medium. CMSC3A1 conditioned medium was fractionated on a HPLC using BioSep S4000, 7.8 mm x 30 cm column. The components in CM were eluted with 20 mM phosphate buffer with 150 mM of NaCl at pH 7.2. The elution mode was isocratic and the run time was 40 minutes. The eluent was monitored for UV absorbance at 220 ηm. Each eluting peak was then analyzed by light scattering. The fastest eluting peak was labelled as the exosome fraction and collected for subsequent analysis. (B) Western blot analysis. Proteins from the lysates of the various MSC lines as well as their HPLC-686 purified exosomes were separated on SDS-PAGE and probed with anti-MYC, anti-ACTB, anti-CD81 and anti- CD9 antibodies.