I have to collect conditioned medium from SACC-LM cell line. I have been collecting the media after growing the cells for 72hrs (once they reach 70% confluency). Is this the right way to do it?after that a collect the protein from the CM , after doing western blot using GADPH i get band but when Tsp-1 not band but when i used the protein collect directly from the cell i have band any onyone have idea?