Hnrnpa2 b1

The EV or cell pellets were re-suspended separately in RIPA buffer supplemented with protease inhibitor (TargetMol, Shanghai, China). Twenty micrograms of protein were then separated on a 10% SDS-PAGE gel (Thermo Fisher, Waltham, MA, USA). Proteins were transferred to a polyvinylidene fluoride (PVDF) membrane and blocked with 5% skim milk in Tween/Tris buffered saline (TTBS) for 1h at room temperature. Membranes were then incubated with primary antibodies against TSG101 (ProteinTech, Wuhan, China), CD9 (ProteinTech), GAPDH (Abcam, Cambridge, MA, USA), hnRNPA2B1 (ProteinTech), Rab27b (ProteinTech), Flag tag (Abcam), or Calnexin (ProteinTech) at a dilution of 1:2000 with 3% skim milk diluted in TTBS for 1h at room temperature. After washing several times with TTBS, membranes were incubated with horseradish peroxidase conjugated goat anti-rabbit IgG secondary antibodies (Santa Cruz Biotechnology, Santa Cruz, CA, USA) at a dilution of 1:10,000 in 3% skim milk dissolved in TTBS for 1 h at room temperature. After washing several times with TTBS, membranes were covered with ECL substrate solution and visualized by exposing to film and developing in a film processor.