Western blot analysis of proteins secreted by COS-7 cells into the growth media using a polyclonal antibody against FVII. From concentrated conditioned media 2.5 μg of protein was electrophoresed on a 10% sodium dodecyl sulfate polyacrylamide gel and transferred to nitrocellulose. The FVII was detected using a polyclonal rabbit anti-human FVII antibody (Stago Asserachrom; Shield Diagnostics) and chemiluminescence detection reagents. Lane 1, vector alone; lanes 2 and 3, ▵EGF 1 FVII; lanes 4 and 5, wt FVII; lanes 6 to 8, 5, 2, and 1 ng purified recombinant wtFVII, respectively; lanes 9 to 12, 5, 10, 20, and 50 ng recombinant FVIIa, respectively. The relative sizes of molecular weight markers are shown in kD.