Figure 5. Western blots using different anti-mouse Cfh antibodies. Goat anti-mouse Cfh (A) and rabbit anti-mouse Cfh (B) antibodies probed against increasing concentrations of human (0.05, 0.1, and 0.2 μg/ml in lanes 2–4, respectively) and mouse (0.05, 0.1, and 0.2 μg/ml in lanes 5–7, respectively) purified complement factor H, and increasing volumes of mouse serum (1, 2.5, 5.0, and 10 μl serum/lane, lanes 8–11, respectively, loaded 40 μl total volume/lane). The goat anti-mouse Cfh antibody recognized human and mouse Cfh, as well as Cfh in mouse serum (A), while the rabbit anti-mouse Cfh antibody recognized only mouse Cfh and Cfh in mouse serum (B). Nonspecific binding by secondary antibodies was tested by primary antibody deletion (Lane 12). Both antibodies used against serum (1 μl/lane) from 129/Sv Cfh^−/− (KO) and their wild-type background strain 129/Sv (WT) recognized Cfh only in serum from the background strain (WT) and C57BL/6 (B6) serum ran as a control (C). Note that both antibodies recognized only one major band at approximately 155 kDa (red arrow), the approximate weight of Cfh.