Characterization of the anti-17βHSD2 antibody. Western blot analysis: Cytosol and microsomes extracted from human placental villi were resolved on a 12% SDS-PAGE and transferred on nitrocellulose membrane. Immunodetection was performed using purified rabbit anti-17βHSD2 antibody (Panel A), preimmune rabbit serum (Panel B), or antibody pre-adsorbed with an excess (10-6M) of 17βHSD2 synthetic polypeptide (Panel C). Specificity of the anti-17βHSD2 antibody was also studied by two-dimensional gel electrophoresis (Panels D and E). Microsomal fraction of placental villi was separated by 2-dimensional isoelectric focusing-SDS-PAGE. Panel D, silver staining. Panel E, immunodetection with the purified anti-17βHSD2 antibody. Position of the circle on panel D corresponds to the location of the circle on panel E. The upper arrow corresponds to a pI value of approximately 8 to 9 and arrow on the right side corresponds to the expected molecular weight.