The distribution of multimerin in transfected HEK 293, COS-1, and AtT 20 cells immunolabeled with polyclonal antimultimerin. Images acquired by standard immunofluorescent microscopy (left and middle panels) and confocal optical sectioning (right panels) are shown. Multimerin was not detected in control cells transfected with the empty vector (panels labeled control). In HEK 293 and COS-1 cells transiently transfected with the multimerin cDNA (panels labeled multimerin), recombinant multimerin was distributed throughout the cytoplasm, without evidence of granule formation. In AtT 20 cells transiently (standard immunofluorescent microscope image) and stably (confocal optical section image) transfected with the multimerin vector, multimerin was predominantly located in small granule-like structures that were most abundant at the distal cell tips (arrowheads; N indicate cell nuclei).