Figure 7: Lipid-association of Hsp70 in exosomes and in the plasma membrane of living tumor cells. (A) An incomplete solubilisation of lipid vesicles such as exosomes with detergents used in ELISA tests can lead to Hsp70-lipid complexes. Lipid-bound Hsp70 that exerts a different conformation can only be detected by cmHsp70.1 mAb but not by other Hsp70-specific antibodies. (B) The cmHsp70.1 mAb detects Hsp70 on the plasma membrane of living tumor cells. This lipid-bound conformation of Hsp70 in the plasma membrane is similar to that of lipid-bound Hsp70 in exosomes. Therefore, we speculate that the recovery of lipid-bound Hsp70 with the lipHsp70 ELISA is better than with the control ELISA.