Fig. 2. Immunolocalization of the V-type H⁺-ATPase in Malpighian tubules of Aedes aegypti. Paraffin sections of mosquito Malpighian tubules were labeled with a polyclonal antibody specific to the 56 kDa B subunit of the V-type H⁺-ATPase (see Fig. 1B). (A) Paraffin section labeled with preimmuno-serum as a negative control. (B) Paraffin section labeled with C23 polyclonal antibody; sc, stellate cell. Scale bar, 100 µm. The inset section illustrates stellate cells without staining. Arrowheads point to small stellate cells without a prominent brush border. Scale bar, 200 µm.