Fig. 2. Accumulation of uPA in MDA-MB-231 cell-conditioned medium. (A) Immunoblot analysis was used to detect uPA in serum-free medium conditioned by MDA-MB-231 cells in the presence or absence of uPA-specific antibody for 24 hours. A standard curve was generated using known amounts of purified uPA (5-50 ng). The low mobility band is assumed to represent uPA-PAI-1 complex, due to the apparent molecular mass. (B) Levels of UPA in CM were quantitated by densitometry, in comparison with the standard curve (n=3).
