Transgenic mice kidneys by immunofluorescence and immunostaining. (A) Homozygous κ-CHEB mice. Immunofluorescence microscopy, polyclonal rabbit antibody against human κ-light chain, original magnification × 400. Strong peripheral staining of crystalline inclusions in the cytoplasm of proximal tubular cells. No staining was observed in glomeruli and distal tubule basement membranes and lumens. Proximal tubular cells were not stained by the anti-λ polyclonal antibody (not shown). (B) Homozygous κ-CHEB mice. Immunostaining with a rabbit polyclonal anti–mouse cathepsin B, original magnification × 1000. Heavy cytoplasmic labeling was observed in proximal tubule sections. Inset: strong peripheral staining of intracytoplasmic vacuoles containing crystalline inclusions (arrows).