Identification by western-blot of recombinant BMP-2, BMP-7 and TGF-β1 from Nicotiana benthamiana leaves. Crude extracts from plants containing each factor and obtained as described in the text were filtered on 0.2 μm membranes and loaded on a HisTrap HP column. Each factor was loaded separately. Fractions were dialyzed against PBS, loaded on a SDS-PAGE gel, transferred to nitrocellulose membranes and incubated with specific rabbit policlonal antibodies to confirm its identity. Molecular weight markers (kDa) are indicated on the left.